Basis Reduction Algorithms and Subset Sum Problems

This thesis investigates a new approach to lattice basis reduction suggested by M. Seysen. Seysen's algorithm attempts to globally reduce a lattice basis, whereas the Lenstra, Lenstra, Lovasz (LLL) family of reduction algorithms concentrates on local reductions. We show that Seysen's algorithm is well suited for reducing certain classes of lattice bases, and often requires much less time in practice than the LLL algorithm. We also demonstrate how Seysen's algorithm for basis reduction may be applied to subset sum problems. Seysen's technique, used in combination with the LLL algorithm, and other heuristics, enables us to solve a much larger class of subset sum problems than was previously possible.

Public internet access revisited

In recent years the Australian government has dedicated considerable project funds to establish public Internet access points in rural and regional communities. Drawing on data from a major Australian study of the social and economic impact of new technologies on rural areas, this paper explores some of the difficulties rural communities have faced in setting up public access points and sustaining them beyond their project funding. Of particular concern is the way that economic sustainability has been positioned as a measure of the success of such ventures. Government funding has been allocated on the basis of these rural public access points becoming economically self-sustaining. This is problematic on a number of counts. It is therefore argued that these public access points should be reconceptualised as essential community infrastructure like schools and libraries, rather than potential economic enterprises. Author Keywords: Author Keywords: Internet; Public access; Sustainability; Digital divide; Rural Australia