This paper proposes a novel method, named Refined Knowledge Transfer (RKT), for language-based person search. Existing state-of-the-art methods do not deal with knowledge imbalance between image and text. In detail, textual identity knowledge is limited, but the image contains more identity knowledge. We propose Cross-Modal Knowledge Transfer (CMKT) to enhance textual identity knowledge by image to address this problem. Besides, multiple texts of one image include more identity knowledge than a single text. Thus, we propose Intra-Modal Knowledge Transfer (IMKT) to enhance textual identity knowledge by other texts. These two types of knowledge transfer will enhance the identity knowledge in text. Additionally, by considering that identity-irrelevant knowledge is transferred to text, we propose Knowledge Refiner (KR) to refine the knowledge in text. KR is capable of preserving identity knowledge and discarding identity-irrelevant knowledge. By combining CMKT, IMKT, and KR, RKT makes textual identity knowledge more salient. Extensive experiments show the state-of-the-art performance of RKT on the CUHK-PEDES and our proposed PRW-PEDES-CN datasets. In addition, the decent generalization ability of RKT is also validated on the Flickr30K, CUB, and Flowers datasets.

Networks are one of the most powerful structures for modeling problems in the real world. Many machine learning algorithms, however, require that each input example is a real vector. Network embedding learns from feature representations of nodes and links in a network, and converts it to vectors. Community structure is an important feature of the network, which represents the relationship among nodes and attracts the attention of relevant researchers. Many algorithms have been developed to identify the community structure. These algorithms usually identify different communities in the network, generating different types of information. In this paper, we propose a "Community Splitter" model based on random walk and RNN (Recurrent Neural Networks) that combines the node information generated by multiple community detection algorithms to improve node representation and link prediction. Extensive experiments on nine real datasets demonstrate that our proposed Community Splitter model has a significant prediction power compared to state-of-the-art link prediction models.