Algorithms now play a very important role for the reliability and efficiency in several social systems. We study and develop new algorithmic techniques from the viewpoint of theoretical computer science. In particular, we deal with several problems related to “graphs” and “circuits.”

  (1) A graph consists of a set of vertices and a set of edges, each of which joins a pair of vertices. Graphs can be used to model many practical problems. For example, in Fig. 1, each vertex corresponds to a router and each edge corresponds to a communication link. Then we can formulate several practical situations as graph problems.

  (2) We consider circuits modeling neural networks in the brain (see Fig. 2). Biological neurons in the brain communicate with each other by firing in order to perform various tasks, but a neuron needs to consume a large amount of energy for firing. By designing and analyzing circuits of low firing activity, we study what structures benefit the energy-efficiency of neural networks.

  Students in our laboratory can select research topics according to their own interests. We study algorithms from the theoretical viewpoint, but we sometimes implement developed algorithms to evaluate them from the practical viewpoint.