# Anomaly Detection in Road Networks Using Sliding-Window Tensor Factorization

## TL;DR

This paper introduces a tensor-based model utilizing sliding-window tensor factorization to detect multiple types of anomalies in road networks, improving traffic management and emergency response capabilities.

## Contribution

It presents a novel, efficient tensor factorization algorithm for multi-type anomaly detection in road networks, including path-level anomaly inference.

## Key findings

- Effective detection of multiple anomaly types demonstrated
- Outperforms baseline methods in synthetic and real-world tests
- Path-level anomaly identification enhances traffic analysis

## Abstract

Anomaly detection in road networks is vital for traffic management and emergency response. However, existing approaches do not directly address multiple anomaly types. We propose a tensor-based spatio-temporal model for detecting multiple types of anomalies in road networks. First, we represent network traffic data as a 3rd-order tensor. Next, we acquire spatial and multi-scale temporal patterns of traffic variations via a novel, computationally efficient tensor factorization algorithm: sliding window tensor factorization. Then, from the factorization results, we can identify different anomaly types by measuring deviations from different spatial and temporal patterns. Finally, we discover path-level anomalies by formulating anomalous path inference as a linear program that solves for the best matched paths of anomalous links. We evaluate the proposed methods via both synthetic experiments and case studies based on a real-world vehicle trajectory dataset, demonstrating advantages of our approach over baselines.

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Source: https://tomesphere.com/paper/1803.04534