電子研学術講演会(Prof. James A. Yorke)

In control theory, someone selects a desirable trajectory, often an equilibrium and then chooses a feedback control that forces that trajectory to be implemented. In a chaotic situation with noise, it is always necessary to have a control that is stronger than the noise so that the noise can be overcome.

In life it is far more common that we want to assure certain situations do not occur. For example, that our company does not become bankrupt, or we do not crash our car. Here I aim to build a simple mathematical model of such situations. Our concept of “partial control” selects one or more possible regions of phase space of a chaotic system to be avoided. We must then ensure that this trajectory never enters these regions. We look at situations where the control is always weaker than the noise.

IKnowing the DNA sequences of the various species has become the foundation for many areas of biology, and it promises to become more important. How to determine the sequence of A,C,G,&T in a species’ DNA was well understood until recently, when the situation suddenly changed. Recently,generating fragments of the sequence for whole genome assembly has become 10,000 times cheaper, but the cheap fragments have much lower quality. As a result the publication of new genomes has slowed. My group specializes in assembling large genomes. I willreport on progress. My group’s current projects include the Indian Cow genome (which as 3 billion bases) and the Loblolly Pine Tree genomes (which has 24 billion bases in its genome).