Xinyi Zhang

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The booming popularity of smartphones is partly a result of application markets where users can easily download wide range of third-party applications. However, due to the open nature of markets, especially on Android, there have been several privacy and security concerns with these applications. On Google Play, as with most other markets, users have direct(More)
Role mining is a very useful engineering method to help administrators set up the mechanism of role based access control for information systems, but not applied in the Android security framework so far. This paper uses large volume Android applications from the Android Market (Google Play Store now), which include 44,971 applications (subjects), 125(More)
Online services are increasingly dependent on user participation. Whether it's online social networks or crowdsourcing services, understanding user behavior is important yet challenging. In this paper, we build an unsupervised system to capture dominating user behaviors from clickstream data (traces of users' click events), and visualize the detected(More)
– As the substrate of structured peer-to-peer systems, Distributed Hash Table (DHT) plays a key role in P2P routing infrastructures. Traditional DHT does not consider the location of the nodes for the assignment of identifiers, which will result in high end-to-end latency on DHT-based overlay networks. In this paper, we propose a design of locality-aware(More)
This paper studies microprocessor floorplanning considering thermal and throughput optimization. We first develop a stochastic heat diffusion model taking into account the application dependent power load for thermal analysis. Then, we design the floorplanning algorithm based on this model. Experimental results show that, compared with the deterministic(More)
An exact formula for the expected length of the minimum spanning tree of a connected graph, with independent and identical edge distribution, is given, which generalizes Steele's formula in the uniform case. For a complete graph, the difference of expected lengths between exponential distribution, with rate one, and uniform distribution on the interval (0,(More)
• Link prediction in large dynamic social networks • Generalizable user behavior profiling using network clickstreams • Measurement/analysis on real-time video streaming services • Measuring text-to-permission fiedlity on Android applications • Role mining algorihm evaluation and improvement in large volume android applications Publications Conferences