  My interest in querying and analysis of data covers data exploration and mining.  We have developed a powerful clustering algorithm called <A HREF="http://www.cs.wisc.edu/~zhang/birch.html"> <B>BIRCH</B></A> for large datasets and a visual data exploration tool called <A HREF="http://www.cs.wisc.edu/~jussi/devise/devise.html"> <B>DEVise</B></A> as part of the  <A HREF="http://www.cs.wisc.edu/condor/NEXT.html"> <B>NEXT!</B></A> project.  A long-standing research interest is the extension of relational database query languages with logic programming features such as structured terms and recursion, and the use of arithmetic constraints to specify data and queries more compactly and efficiently. An ongoing project involves the continued development and use of the CORAL deductive system.  The evaluation is based upon bottom-up fixpoint evaluation techniques, and several optimizations are applied to make it efficient across a broad range of programs. <p>
