Locality Preserving Projections for Grassmann manifold

Learning on Grassmann manifold has become popular in many computer vision tasks, with the strong capability to extract discriminative information for imagesets and videos. However, such learning algorithms particularly on high-dimensional Grassmann manifold always involve with significantly high computational cost, which seriously limits the applicability of learning on Grassmann manifold in more wide areas. In this research, we propose an unsupervised dimensionality reduction algorithm on Grassmann manifold based on the Locality Preserving Projections (LPP) criterion. LPP is a commonly used dimensionality reduction algorithm for vector-valued data, aiming to preserve local structure of data in the dimension-reduced space. The strategy is to construct a mapping from higher dimensional Grassmann manifold into the one in a relative low-dimensional with more discriminative capability. The proposed method can be optimized as a basic eigenvalue problem. The performance of our proposed method is assessed on several classification and clustering tasks and the experimental results show its clear advantages over other Grassmann based algorithms.Comment: Accepted by IJCAI 201

Research on Word Segmentation for Chinese Sign Language

PACLIC 20 / Wuhan, China / 1-3 November, 200

Experimental Study of Smoke Spread in Titled Urban Traffic Tunnels Fires

AbstractMore and more urban traffic tunnels are built due to the heavy traffic in dense urban areas. Fire safety in tunnels is a concern due to the large traffic flow. Most of the urban tunnels have slope. Knowledge on smoke spread in titled tunnel is still limited. Experimental studies on the smoke spread in a titled tunnel are carried out by the reduced-scale tunnel model tests and will be discussed in this paper. Effects of the titled gradients and longitudinal ventilation speed on the temperature distribution and smoke stratification downstream from the fire along the tunnel will be studied The results show that the smoke spread upwards much faster with the slop gradient increasing, and a thick smoke layer was formed when smoke moved to the upward part of the tunnel and filled it up. The ventilation speed had a great influence on temperature distribution along the tunnel, and the smoke stratification will be distributed when the longitudinal ventilation speed becomes large. Lower ventilation speed should be adopted at the beginning to ensure the smoke downstream of the fire keep stratified to give the tunnel users more time to escape