Self-introduction
Hello, I’m NAKAJIMA, Shohei, from SILS at Waseda. I have been attending Waseda since I was an undergraduate student.
My interest is quite simple: “I want to understand the world”. When I was in high school, I encountered Newton’s equations of motion and was shocked. By using the equations of motion, once the initial conditions are given, the motion can be unambiguously determined, in other words, the future can be predicted. I was struck by the beauty of the system and immersed myself in the study of physics and mathematics. I really thought that if I followed this path, I could hold the whole world in my hands.
But of course, the world is not so easy. When I returned from the abstract world of physics and mathematics, I could not help but be perplexed by the reality there, which was full of things that could not be understood in the language of mathematics and physics. Yes, for example, human relationships and uncertainty about one’s future.
My original ambition has become much smaller, but my interest has not changed much: “I want to understand at least one part of the world.” That’s how I continued my studies, and before I knew it, I was a researcher. When I was little, I never dreamed that become a researcher, so you never know what life has in store for you.
Recent Research Interests
Mathematically, time-series phenomena with random movements in the world can be modeled as a sequence of random variables. A family of random variables that move “randomly” with respect to changes in time is called a “stochastic process”. Theoretical research on stochastic processes is called “stochastic analysis,” starting with typical stochastic processes such as Brownian motion and Poisson processes, and developing into martingale theory, theory of stochastic differential equations, etc.
When modeling various phenomenon using stochastic processes, unknown parameters always appear. These must be determined statistically, taking into account past observations and various external factors. I am working on so-called “mathematical statistics,” which uses historical data to construct an “estimator” for each parameter and then mathematically and statistically explain the goodness of the estimator. The tools of stochastic analysis are also useful in examining the mathematical properties of these estimators.
Profile
Bachelor’s Degree (2015~2017), Master’s Degree (2017~2019) and Ph.D. (2019~2023) in Science received from Waseda University. Worked as Research Associate at Waseda University from 2021~2023. Current position as of April 2023.
