REST:一种基于参考的时空轨迹压缩框架REST: A Reference‑based Framework for Spatio‑temporal Trajectory Compression |
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课程网址: | http://videolectures.net/kdd2018_zhao_rest_reference/ |
主讲教师: | Yan Zhao |
开课单位: | 东吴大学计算机科学与技术学院 |
开课时间: | 2018-11-23 |
课程语种: | 英语 |
中文简介: | 支持GPS的设备和无线通信技术的普及导致了大量的轨迹数据,导致了存储、传输和查询处理的昂贵成本。为了解决这个问题,在本文中,我们提出了一种新的压缩轨迹数据的框架,REST(基于参考的时空轨迹压缩),通过该框架,原始轨迹由一系列历史(子)轨迹(称为参考轨迹)的串联来表示,这些轨迹在给定的时空偏差阈值内形成压缩轨迹。为了构建最有利于后续压缩的参考轨迹集,我们提出了三种技术,以从大数据集中明智地选择参考轨迹,从而使生成的参考集更紧凑,但覆盖了感兴趣区域中轨迹的大部分足迹。为了解决由于类似给定轨迹而可能存在的参考轨迹的大量组合所导致的计算问题,我们提出了在眨眼间运行的高效贪婪算法和可以实现最佳压缩比的动态编程算法。与现有的轨迹压缩工作相比,我们的框架几乎没有关于数据的假设,例如在道路网络内移动或以恒定方向和速度移动,并且在相当小的时空损失下具有更好的压缩性能。在真实滑行轨迹数据集上的大量实验表明,在压缩比和效率方面,我们的框架优于现有的代表性方法 |
课程简介: | The pervasiveness of GPS-enabled devices and wireless communication technologies results in massive trajectory data, incurring expensive cost for storage, transmission, and query processing. To relieve this problem, in this paper we propose a novel framework for compressing trajectory data, REST (Reference-based Spatio-temporal trajectory compression), by which a raw trajectory is represented by concatenation of a series of historical (sub-)trajectories (called reference trajectories) that form the compressed trajectory within a given spatio-temporal deviation threshold. In order to construct a reference trajectory set that can most benefit the subsequent compression, we propose three kinds of techniques to select reference trajectories wisely from a large dataset such that the resulting reference set is more compact yet covering most footprints of trajectories in the area of interest. To address the computational issue caused by the large number of combinations of reference trajectories that may exist for resembling a given trajectory, we propose efficient greedy algorithms that run in the blink of an eye and dynamic programming algorithms that can achieve the optimal compression ratio. Compared to existing work on trajectory compression, our framework has few assumptions about data such as moving within a road network or moving with constant direction and speed, and better compression performance with fairly small spatio-temporal loss. Extensive experiments on a real taxi trajectory dataset demonstrate the superiority of our framework over existing representative approaches in terms of both compression ratio and efficiency |
关 键 词: | GPS的设备; 无线通信技术; 参考轨迹集; 轨迹的大量组合 |
课程来源: | 视频讲座网 |
数据采集: | 2023-03-09:cyh |
最后编审: | 2023-05-15:cyh |
阅读次数: | 36 |