Abstract:Studies in social network theory focus on characterizing complex social relationships by firstly mapping and visualizing them into a graph, and then subsequently identifying the corresponding graph properties. This paper provides an integrated approach, which combines social network analysis and data mining theory with the necessary geographical attributes to analyze 1417 instances of terrorism that occurred world wide during the period 1980-2002. The study reveals interesting patterns on the evolution of these terrorist organizations over two decades. The proposed method can be easily generalized to be applied to other types of large-scale networked datasets, such as micro-array data, and genomic networked data, etc.

Abstract:A key issue in one-way delay measurement is the removal of relative clock offset in the situation of without external clock synchronization mechanisms for the end-to-end hosts. Most researches are based on the assumption that the clock skew retains constant and without clock adjustments and drifts during measurement. But in fact, it is found that end system clock might be subject to gradual or instantaneous clock adjustments and frequency adjustments in operation. In this paper, with the time series segmentation technology, we discuss the detection of clock dynamics in one-way delay measurement. Two algorithms are proposed to estimate the relative clock offset in post facto and on-line mode respectively, while with only unidirectional probe packets. The computational complexity of the post facto algorithm is of order O(N2). Experiments show that these algorithms can provide reasonable clock dynamics detection and informative one-way delay estimation.