How to Compare the Scientific Contributions between Research Groups

We present a method to analyse the scientific contributions between research groups. Given multiple research groups, we construct their journal/proceeding graphs and then compute the similarity/gap between them using network analysis. This analysis can be used for measuring similarity/gap of the topics/qualities between research groups' scientific contributions. We demonstrate the practicality of our method by comparing the scientific contributions by Korean researchers with those by the global researchers for information security in 2006 - 2008. The empirical analysis shows that the current security research in South Korea has been isolated from the global research trend

Hybrid Spam Filtering for Mobile Communication

Spam messages are an increasing threat to mobile communication. Several mitigation techniques have been proposed, including white and black listing, challenge-response and content-based filtering. However, none are perfect and it makes sense to use a combination rather than just one. We propose an anti-spam framework based on the hybrid of content-based filtering and challenge-response. There is the trade-offs between accuracy of anti-spam classifiers and the communication overhead. Experimental results show how, depending on the proportion of spam messages, different filtering %%@ parameters should be set.Comment: 6 pages, 5 figures, 1 tabl

Fluid Patterning in a Cavity Array for High-Throughput Screening and Biotechnological Applications

Biomedical EngineeringOver the past few decades, fundamental biological understanding has advanced significantly with the help of experimental biotechnologies. Among them, synthetic biology as a rising research field has shown its capability for building new microorganisms from the scratch. In conjunction with synthetic biology, directed evolution techniques seem to be highly useful for industrial purposes such as the over-production of chemical products such as biofuels, which are expected to resolve global energy problems. However, it still requires a high-throughput screening technique and/or compartmentalized environments for cell sorting. In this thesis, two microfluidic technologies are described. First, a novel microdroplet trapping technology is developed that utilizes the difference of specific gravity between two immiscible fluids to offer simple and easy manipulation of microdroplets for time-traceable single microorganism analysis. Second, a high-throughput screening technology is developed by patterning fluid, in which individual Escherichia coli cells can be immobilized and cultured in a cavity array format. It is noted that the cavities were coated with parylene and bonded with another parylene layer to secure chemical compatibility. In addition, it was successfully demonstrated that the two technologies hold a high potential to enable not only high-throughput screening but also many biological experiments such as detection of cell-excreted products, long-term cell incubation, cell to cell communication, and detection of target molecules via a whole cell biosensor.ope