Jiannan Zhai

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Networking concepts have been in use for centuries. The human body is a network of organs that must coordinate to survive. The postal service is an example of a network that connects individuals world-wide. It is only natural that networks play an important role in computing --- from networks of sensors collecting and recording data, to social networks, to(More)
Network simulation is an important tool for testing and evaluating wireless sensor network applications. Parallel simulation strategies improve the scalability of these tools. However, achieving high performance depends on reducing the synchronization overhead among simulation processes. In this paper, we present an optimistic simulation algorithm with(More)
Computational thinking represents a collection of structured problem solving skills that cross-cut educational disciplines. There is significant future value in introducing these skills as early as practical in students' academic careers. Over the past three years, we have developed, piloted, and evaluated a series of K-12 outreach modules designed to(More)
Imbalanced data existed widely in various fields. The classification problem of imbalanced data is a hot issue in machine learning. Existing algorithms on imbalanced data classification processed data without putting enough attention on the positive boundary samples which were prone to misclassification, and the cost that the positive samples were(More)
Sensors have become pervasive throughout our daily activities. Virtually all appliances use one or more sensors. Networks of sensors are used to support home and medical monitoring, wildlife behavioral monitoring, military applications, and environmental management. Observing the value of sensors in computing, we developed the third in a series of serious(More)