Many of our seminars are Pure Mathematics Colloquia, so why not check here?

## Previous CIRCA & Algebra Semigroups - 2016 to 2017

Previous Pure Mathematics Colloquia from: 2016/17, 2015/16, 2014/15, 2013/14, 2012/13, 2011/12, 2010/11, 2008/09, 2007/08**Wednesday the 8th of March 2017 at 1pm in Theatre D**

Tomas Nilson
*Mid-Sweden University
***Agrawalâ€™s conjecture for triple arrays
**

A triple array is an array in which two 2-designs are merged together such that any row and column contain the same number of common symbols.

Agrawalâ€™s conjecture says that (in the canonical case), there is a triple array if and only if there is a symmetric 2-design (SBIBD).

Given a triple array we can construct a SBIBD. But here we will look at approaches and problems surrounding the desirable and still open direction. How to construct an array with these properties from a subset structure.

We will give background and define objects used. The exposition will be elementary and special knowledge of the area will not be assumed.

**Friday the 24th of February 2017 at 2pm in Lecture Theatre A**

Robert Bailey
*Memorial University of Newfoundland
***Metric dimension, computation and distance-regular graphs
**