4 papers
An algebraic-combinatorial framework for finding the average hitting times in graphs with high regularity
Aida Abiad, Yusaku Nishimura
For any given vertices and in a graph, the hitting time of a random walk on a finite graph is the number of steps it takes for a random walk to reach vertex starting at…
A New Approach to Code Smoothing Bounds
Tsuyoshi Miezaki, Yusaku Nishimura, Katsuyuki Takashima
Code smoothing is a phenomenon in which an error distribution makes a code statistically close to the uniform distribution over the ambient space. This closeness is measured by the…
On Lattice Isomorphism Problems for Lattices from LCD Codes over Finite Rings
Yusaku Nishimura, Katsuyuki Takashima, Tsuyoshi Miezaki
These days, post-quantum cryptography based on the lattice isomorphism problem has been proposed. Ducas-Gibbons introduced the hull attack, which solves the lattice isomorphism pro…
Universal graph series, chromatic functions, and their index theory
Tsuyoshi Miezaki, Akihiro Munemasa, Yusaku Nishimura +2
In the present paper, we introduce the concept of universal graph series. We then present four invariants of graphs and discuss some of their properties. In particular, one of thes…