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We study the problem of clustering data objects whose locations are uncertain. A data object is represented by an uncertainty region over which a probability density function (pdf) is defined. One method to cluster uncertain objects of this sort is to apply the UK-means algorithm, which is based on the traditional K-means algorithm. In UK-means, an object(More)
Medical image compression can significantly enhance the performance of picture archiving and communication systems and may be considered an enabling technology for telemedicine. The wavelet transform is a powerful mathematical tool with many unique qualities that are useful for image compression and processing applications. Although wavelet concepts can be(More)
Many kinds of real-life data exhibit logical ordering among their data items and are thus sequential in nature. However, traditional online analytical processing (OLAP) systems and techniques were not designed for sequence data and they are incapable of supporting sequence data analysis. In this paper, we propose the concept of Sequence OLAP, or S-OLAP for(More)
The interaction between usability and how a web site is structured is a complicated issue. In this paper, we discuss a web structure mining algorithm which allows the automatic extraction of navigational structures in a website without performing hypertext analysis. We perform several usability experiments to correlate the usability of web sites and the(More)
The Sequence OLAP (S-OLAP) system is a novel online analytical processing system for analyzing sequence data. S-OLAP supports "pattern-based" grouping and aggregation on sequence data - a very powerful concept and capability that is not supported by traditional OLAP systems. It also supports several new OLAP operations that are specific to sequence data(More)
Order-preserving submatrices (OPSM's) have been shown useful in capturing concurrent patterns in data when the relative magnitudes of data items are more important than their exact values. For instance, in analyzing gene expression profiles obtained from microarray experiments, the relative magnitudes are important both because they represent the change of(More)