Zero-Shot Event Detection by Multimodal Distributional Semantic Embedding of Videos

We propose a new zero-shot Event Detection method by Multi-modal Distributional Semantic embedding of videos. Our model embeds object and action concepts as well as other available modalities from videos into a distributional semantic space. To our knowledge, this is the first Zero-Shot event detection model that is built on top of distributional semantics and extends it in the following directions: (a) semantic embedding of multimodal information in videos (with focus on the visual modalities), (b) automatically determining relevance of concepts/attributes to a free text query, which could be useful for other applications, and (c) retrieving videos by free text event query (e.g., "changing a vehicle tire") based on their content. We embed videos into a distributional semantic space and then measure the similarity between videos and the event query in a free text form. We validated our method on the large TRECVID MED (Multimedia Event Detection) challenge. Using only the event title as a query, our method outperformed the state-of-the-art that uses big descriptions from 12.6% to 13.5% with MAP metric and 0.73 to 0.83 with ROC-AUC metric. It is also an order of magnitude faster.Comment: To appear in AAAI 201

Analysis of mode localization in a single-layer spherical reticulated shell

The occurrence of the mode localization is studied in a structure of a single-layer spherical reticulated shell. The matrix perturbation method is used to analyze the mechanism of the occurrence of mode localization. The dynamical characteristics of this structure, especially the effects of the variation of the stiffness parameter on the vibration modes of the structure, were analyzed by numerical simulations. An amplitude significance coefficient is proposed as a measure of the degree of the mode localization. The results show that small deviations of the stiffness parameter can cause significant changes to the structural dynamics characteristics; the mode localization does occur for some particular modes of this structure in the case of random stiffness mistuning. Preliminary analysis found that the mode can be considered as strongly localized when the amplitude significance coefficient is greater than 8