Masaaki Sugihara (1954–2019) — Japanese researcher in numerical analysis

Research areas and characteristics

• Numerical analysis: methodological foundations and error estimation for algorithms.
• Numerical linear algebra: study of matrix computations, stability and iterative methods.
• Numerical integration: development and analysis of quadrature rules and transforms that accelerate convergence.
• Approximation theory: construction and evaluation of function approximations, including Sinc-type approaches and related transforms.

Career and collaborations

Sugihara spent much of his academic career at the University of Tokyo, where he taught and supervised students in computational mathematics. He coauthored several studies with colleagues in Japan and abroad; most notably, he collaborated with Masatake Mori on analysis and improvements of exponential-type transformations for numerical integration. Their joint work helped popularize techniques that combine analytic transformations with discretization to achieve high accuracy for integrals with endpoint singularities or infinite domains.

Notable methods and contributions

Sugihara contributed to a body of techniques that make numerical computations more robust and efficient. His publications examined how particular transforms and approximation bases affect convergence and round-off error. He explored Sinc-based approximation frameworks and the use of double-exponential and related mappings to compress difficult integrand behavior into forms more amenable to simple quadrature rules. These ideas have been influential in contexts where high precision or guaranteed error bounds are required.

Impact, applications and distinctions

The practical consequence of Sugihara's work is visible in improved algorithms for evaluating integrals, solving boundary-value problems numerically, and reducing computational cost while controlling error. Such advances are relevant across scientific computing, engineering simulations, and mathematical software. His collaborations and papers are often cited in subsequent methodological studies and software implementations that adopt transformed quadrature or Sinc-based approximations.

Further reading

For introductions to the broader areas central to Sugihara's work, see resources on numerical analysis, numerical linear algebra and numerical integration. Materials that treat Sinc approximation and exponential transforms provide context for his contributions to approximation theory and his collaborations with Masatake Mori.