Robots navigating in human crowds need to optimize their paths not only for their task performance but also for their compliance to social norms. One of the key challenges in this context is the lack of standard metrics for evaluating and optimizing a socially compliant behavior. Existing works in social navigation can be grouped according to the differences in their optimization objectives. For instance, the reinforcement learning approaches tend to optimize on the comfort aspect of the socially compliant navigation, whereas the inverse reinforcement learning approaches are designed to achieve natural behavior. In this paper, we propose NaviGAN, a generative navigation algorithm that jointly optimizes both of the comfort and naturalness aspects. Our approach is designed as an adversarial training framework that can learn to generate a navigation path that is both optimized for achieving a goal and for complying with latent social rules. A set of experiments has been carried out on multiple datasets to demonstrate the strengths of the proposed approach quantitatively. We also perform extensive experiments using a physical robot in a realworld environment to qualitatively evaluate the trained social navigation behavior. The video recordings of the robot experiments can be found in the link: https://youtu.be/61blDymjCpw.

Nowadays, with the success and fast growth of social media communities and mobile devices, people are encouraged to share their multimedia data online. Analyzing and summarizing data into useful information thus becomes increasingly important. For online photo sharing services like Flickr, when users are uploading a batch of daily photos at a time, the tags users provided tend to be rather vague, containing only a small amount of information. For better photo application and understanding, we attempt to automatically discover semantic-rich (hidden) aspects of photos merely by looking at image contents. In this paper, we propose an effective model, which is a combination of LDA model and deep learning representations, to realize the idea of automatic aspect discovery. We then discuss the properties of this aspect discovery model through experiments on event summarization task. In those experiments, we show the high diversity and high quality of aspects discovered by our proposed method. Meanwhile, we conduct an user study to evaluate the quality of the summarized results. Moreover, the proposed method can be further extended to human attribute discovery for a given event. We automatically discover different aspects on our Olympic Games data (e.g. football, ice skating).

Recently, the fast growth of social media communities and mobile devices encourages more people to share their media data online than ever before. Analyzing data and summarizing data into useful information have become increasingly popular and important for modern society. Given a set of event keywords and a dataset, this paper performs event summarization, aiming to discover and summarize what people may concern for each event from the given dataset. More specifically, this paper extracts latent sub-events with diverse and representative attributes for each given event. This paper proposes effective methods on detecting events with (1) human attribute discovery, such as human pose and clothes, (2) scene analysis, (3) image aspect discovery, and (4) temporal and semantic analysis, to provide people different perspectives for the events they are interested in. For practical implementation, this paper studied and conducted experiments on YFCC100M, which is a dataset with 100 million of photos and videos, provided by Yahoo!. Finally, a comprehensive and complete system is created accordingly to support diverse event summarization.