Truss Decomposition in Massive Networks

The k-truss is a type of cohesive subgraphs proposed recently for the study of networks. While the problem of computing most cohesive subgraphs is NP-hard, there exists a polynomial time algorithm for computing k-truss. Compared with k-core which is also efficient to compute, k-truss represents the "core" of a k-core that keeps the key information of, while filtering out less important information from, the k-core. However, existing algorithms for computing k-truss are inefficient for handling today's massive networks. We first improve the existing in-memory algorithm for computing k-truss in networks of moderate size. Then, we propose two I/O-efficient algorithms to handle massive networks that cannot fit in main memory. Our experiments on real datasets verify the efficiency of our algorithms and the value of k-truss.Comment: VLDB201

Optimizing the Learning Order of Chinese Characters Using a Novel Topological Sort Algorithm

We present a novel algorithm for optimizing the order in which Chinese characters are learned, one that incorporates the benefits of learning them in order of usage frequency and in order of their hierarchal structural relationships. We show that our work outperforms previously published orders and algorithms. Our algorithm is applicable to any scheduling task where nodes have intrinsic differences in importance and must be visited in topological order

The economics of two-sided payment card markets: pricing, adoption and usage

This paper provides a new theory for two-sided payment card markets by positing better microfoundations. Adopting payment cards by consumers and merchants requires a fixed cost, but yields lower marginal costs of making payments. Considering this together with the heterogeneity of consumer income and merchant size, our theory derives card adoption and usage pattern consistent with cross-section and time-series evidence. Our analyses also help explain the observed card pricing pattern, particularly the rising merchant (interchange) fees over time. This is because a private card network, besides internalizing the two-sided market externality, has the incentive to inflate the card transaction value. We show that privately determined card pricing, adoption and usage tend to deviate from the social optimum, and imposing a ceiling on interchange fees may improve consumer welfare. ; Also issued as a Payments System Research Working Paper.

The investigation of fibre reinforcement effects in thermoplastic materials: interfacial bond strength and fibre end parameter

Glass fibres used in the manufacture of fibre reinforced thermoplastic composites (FRTP) are normally sized with a film former which includes a silane coupling agent to improve the interfacial bond strength between glass fibre and matrix . However, during composite failure even an optimized interface cannot stop the initia tion of cracks at the fibre ends, which can lead to large transverse cracks in the matrix or failure by fibre pull-out. In order to help better understand the failure mechanisms of FRTP, thermoplastic microbond tests and photoelasticity experiments have been used to study the interface in model single fibre composites