We study the following problem on recon guring shortest paths in graphs: Given two shortest st paths, what is the minimum number of steps required to transform one into the other, where each intermediate path must also be a shortest s-t path and must di er from the previous one by only one vertex. We prove that the shortest recon guration sequence can be exponential in the size of the graph and...

Fault Detection and Isolation (FDI) problems are here considered for linear systems with faults and disturbances. We design a set of observer-based residuals, in such a way that the transfer from the disturbances to the residuals is zero and the transfer from the faults to the residuals allows fault isolation. We are interested in obtaining a transfer function from faults to residuals with eith...

We introduce a set of stellar models for massive stars whose evolution has been affected by mass transfer in a binary system, at a range of metallicities. As noted by other authors, the effect of such mass transfer is frequently more than just rejuvenation. We find that, whilst stars with convective cores which have accreted only H-rich matter rejuvenate as expected, those stars which have accr...