Ken-ichi TANAKAtanaka Lab.

Overview of Research

This laboratory focuses on developing mathematical models for analyzing and optimizing the performance of the various types of systems underpinning the society. Our aim is to provide solutions to various optimization problems to assist public and private sector decision makers. Recent research topics include spatial optimization, facility location, and network design problems. We also strongly emphasize applying our models to solve real-life problems.

Major Taught Courses

Operations Research I, Operations Research II

1.Facility location models

Several types of facilities exist in cities, such as convenience stores, ATMs, post offices, and fire stations. The facility location problems aim to find optimal locations of these facilities for user accessibility or maximize facility market share. In our laboratory, we develop new mathematical location models and conduct case studies using geographical data. In particular, we focus on developing extensions to the flow-interception location models, in which the demand for service arises from a traffic flow between the origin and destination in a transportation network.

2.Optimal design of networks and cities

The topology of urban networks, such as road and railway networks, has a significant impact on the convenience of the public using them. We strive to design efficient transportation networks using optimization methods. Another important class of design problem we investigate includes districting problems, which optimally divide a given area into numerous subdistricts to achieve multiple distance-related objectives. We formulate new districting problems on a continuous plane and solve them using mathematical optimization methods.

Recent Research Themes

• Facility location models focusing on flow-based demands
• Optimization models to design safe walking routes for school children
• Visualization of geographical and spatial flow data using optimization methods
• Design of urban topology for maximizing the number of walking-only trips

Educational Policies

We encourage students to develop the ability to independently analyze real-life problems and build their own mathematical models through seminars hosted in our laboratory. Studying various mathematical methods is important to develop the skills required to write computer programs for solving problems and to be able to apply them to actual situations. These abilities allow students not only to conduct research, but also help them to assume important societal roles. At the seminars conducted in our laboratory, we create an environment in which active sharing of ideas and discussions among participants occur easily.