Cross-Domain Image Retrieval with Attention Modeling

With the proliferation of e-commerce websites and the ubiquitousness of smart phones, cross-domain image retrieval using images taken by smart phones as queries to search products on e-commerce websites is emerging as a popular application. One challenge of this task is to locate the attention of both the query and database images. In particular, database images, e.g. of fashion products, on e-commerce websites are typically displayed with other accessories, and the images taken by users contain noisy background and large variations in orientation and lighting. Consequently, their attention is difficult to locate. In this paper, we exploit the rich tag information available on the e-commerce websites to locate the attention of database images. For query images, we use each candidate image in the database as the context to locate the query attention. Novel deep convolutional neural network architectures, namely TagYNet and CtxYNet, are proposed to learn the attention weights and then extract effective representations of the images. Experimental results on public datasets confirm that our approaches have significant improvement over the existing methods in terms of the retrieval accuracy and efficiency.Comment: 8 pages with an extra reference pag

Efficient Spatial Keyword Search in Trajectory Databases

An increasing amount of trajectory data is being annotated with text descriptions to better capture the semantics associated with locations. The fusion of spatial locations and text descriptions in trajectories engenders a new type of top-$k$ queries that take into account both aspects. Each trajectory in consideration consists of a sequence of geo-spatial locations associated with text descriptions. Given a user location $\lambda$ and a keyword set $\psi$, a top-$k$ query returns $k$ trajectories whose text descriptions cover the keywords $\psi$ and that have the shortest match distance. To the best of our knowledge, previous research on querying trajectory databases has focused on trajectory data without any text description, and no existing work has studied such kind of top-$k$ queries on trajectories. This paper proposes one novel method for efficiently computing top-$k$ trajectories. The method is developed based on a new hybrid index, cell-keyword conscious B$^+$-tree, denoted by \cellbtree, which enables us to exploit both text relevance and location proximity to facilitate efficient and effective query processing. The results of our extensive empirical studies with an implementation of the proposed algorithms on BerkeleyDB demonstrate that our proposed methods are capable of achieving excellent performance and good scalability.Comment: 12 page

Financial inclusion from the perspective of basic banking services and consumer credit: a comparative study of law and regulation in the United Kingdom and China

The purpose of this thesis is to study the role and effectiveness of law and regulation in relation to the problem of financial exclusion. The research was conducted through a comparative study of the United Kingdom (hereinafter ‘UK’) and China, and focuses on whether law and regulation could fulfil a role in facilitating vulnerable consumer’s access to basic banking services. The thesis begins with an overview of the theory of financial exclusion and provides definitions of consumer vulnerability. It reviews the exclusion conditions in both countries in respect of basic payment services and consumer credit, and analyses the reasons for, and negative consequences of, being excluded from such services. The thesis then demonstrates the theory of equal opportunity, and the role of law and regulation in the context of facilitating financial inclusion, followed by an overview of credit regulation from a historical perspective. The main content of this thesis is divided into three major parts. The experiences of the UK, China and the European Union (hereinafter ‘EU’) are analysed, and it is found that the process of financial inclusion could be facilitated by way of regulation. First, commercial banks are at the centre of the mainstream market. However, their role in financial inclusion largely focuses on payment services. Whether vulnerable customers’ access to payment services could be facilitated by regulations is the main content of chapter two. This thesis suggests that without enough incentive, banks can be less motivated in this progress. To accelerate financial inclusion in respect of consumer credit, alternative credit facilities on the consumer market should be supported by law and regulation, available funding should be made available and regulatory barriers be removed. After a comprehensive review of their legal and regulatory environment, the present research suggests that the UK has generally made good progress in this regard, while China is still in the nascent stage of development. The weakness in a ‘one-size-fits-all’ model is clarified through the analysis. Subprime lenders are also essential in the market because they fill a gap. Standards that regulate subprime lenders should be equal for all lenders in the market, but also give consumers in the high-risk subprime lending sector. In the case of detriment, the regulatory regime would be able to provide recovery or simple and easy dispute resolution. This thesis argues for both ex ante and ex post consumer protection

Towards Understanding the Schema in Relational Databases

Ph.DDOCTOR OF PHILOSOPH