In the case of metal materials are machined, the surface of materials are plastic defomed. Cristal structure of metal surface is strained by plastic deformation. The crystal structure strain changes the chemical property of surface. This phenomenon is called a mechano-chemical reaction. We study the mechano-chemical reaction and the relationship of machining process and material property.

In order to improve the performance of various industrial devices and to make effective use of energy, it is important to understand and control the mechanisms of momentum, heat, and mass transport by turbulent flows. Understanding of turbulent transport phenomena is also essential for accurate prediction of meteorological phenomena. Our specific research topics include: experiments and numerical simulations to elucidate the mixing mechanism of scalars in liquid-phase turbulent jets; measurements of momentum, heat, and mass transport across wind-wave air-water interfaces to improve the prediction accuracy of typhoons; experiments to elucidate the behavior of droplets and bubbles in turbulent flows; and the development of novel devices (plasma actuators) to reduce fluid friction drag.

The mechanical and electro-magnetic characteristics of metals are dependent on microstructures such as crystal orientation and grain diameter. In recent years, comprehensive studies have been carried out on thermo-mechanical control processing to improve physical properties of metallic materials without adding rare elements in order to save energy and resources. For example, high performance metals, such as ultrafine grain steel and magnetic steel, are developed by a combination of rolling and heat treatment. These metals exhibit uniform characteristics. However, it is more efficient if suitable characteristics can be generated at required positions. In our research, a new technology to control only material surface microstructure is being studied.

Ashworth scales have been used as a method to evaluate the muscle tonus of the patient having spasticity.This method however cannot evaluate it without the enforcer’s subjective judgment.Therefore we analyze the motion of leg by measuring pendulum motion (Pendulum Test) to evaluate the spasticity objectively.

The picture shows two one axis accelerometer were attached to a leg to measure leg motion.Because the angle output of the leg is only provided by the motion capture directly, 2 times differential calculus operation is necessary to obtain the angular acceleration output convenient to evaluate.In contrast, the angular acceleration output is provided directly with our method.

Electronic devices, for example LSI, and so on, are constructed of microscopic electronic circuits formed on semiconductor surfaces. Recently, nano-technology makes the sclae of the components of the microscopic electronic circuits nano-meter scale and makes the devices small, low-cost, and high-performance. We performe the theoretical study of the solid surfaces which handles fundamental properties of the nano-devices. Particularly, we forcus the syufy of the nano-scale structure as molecular gears or atomic chains on solid surfaces with the first principles calculations.

The application of superconductors makes it possible to develop superconducting motors with an unprecedentedly large power-to-gravity ratio. In our laboratory, we are developing superconducting motors with high energy density, such as jet engines, exceeding 10 kW/kg power-to-weight ratio by applying thin-film high-temperature superconducting wires to superconducting armatures.

Multifarious systems are devoloped for induction motor or interior permanent magnetic synchronous motor drives. The systems are implemented by a microcomputer which has 32bit floating point units and multi-function timer units. The methods for estimating the motor speed or weaken flux current have been proposed.

High temperature superconducting (HTS) wires have good characteristics such as perfect electric conductivity and large critical current density. Therefore the HTS wires are expected to contribute to development of small, lightweight and very efficient electric power apparatus. I am currently conducting researches on development of a small power source with an HTS transformer for supplying large current, a protection system for normal transitions in superconducting coils and a superconducting rotating gantry for heavy ion therapy.

The efficiency and performance of many industrial control systems depend on embedded servocontrollers. However, the presence of non-linear, time-varying unmeasurable disturbanses often lead to inability of the system to achieve low values of steady state error and may limit the closed loop bandwidth. Hence, the disturbance rejection is one of the most important and applicable design problem. I work in design and analysis of intelligent control systems including online identification of unknown system model parameters and rejection of unmeasurable disturbances. Another major research topic is development of intelligent UAV (drones) robots and their application in autonomous inspection of electrical energy transmission facilities, buildings etc..

Global motion in images arises with video camera movement. Estimation of global motion is required for image stabilization, image coding, moving object detection, and so on. We develop a fast and accurate method to estimate global motion from an image sequence that contains moving objects (local motion).

Visible light communication (VLC) is a novel optical wireless communication technique that uses blinking of visible light. This technique can not only provide light but also broadcast data. In this study, we develop a VLC system using an LED traffic light and brake lamp (transmitter) and an in-vehicle high-speed image sensor (receiver) for an intelligent transport system (ITS). We refer to this VLC system as image-sensor-based VLC. This system contributes to exchange a safety information between roadway infrastructure (or vehicle) and vehicles.

I perform the spectroscopic analysis in the ionic conductor and the applied study (ionics, photoionics, hydrogen storage material etc.) using it.

The major contents related to the research are shown in the following:
(1) Optical characteristic (refractive index, optical absorption) of the superionic conductior glasses (SICG).
(2) Infrared absorption of perovskite-type proton conductor.

With the spread of Mobile Mapping System (a vehicle equipped with GNSS, laser scanners and cameras), huge point clouds are being accumulated rapidly. My study is to make effective use of this data in current road-related measurement system. And also I’m trying to display this as a high-speed 3DCG via the Internet.

Metaheuristic algorithms such as simulated annealing, iterated local search, genetic evolutionary algorithms are known to be effective optimization methods that can be used for various problems in engineering field. Our research interests are developments, improvements and analyses of high-performance evolutionary algorithms and metaheuristic algorithms based on local search for optimization problems such as Maximum Clique Problem, Graph Coloring Problem, Quadratic Assignment Problem, Facility Location Problem, Vehicle Routing Problem, Scheduling Problems, etc.

I am currently conducting researches on pedestrian flow modeling, simulation, and optimization. There are two reasons for investigating pedestrian flow. One is to solve the day-to-day problems of crowded public spaces, such as stations, shopping malls, pavements and many other places. The other is to optimize evacuation procedures from densely buildings and urban centers in case of an unpredicted event.

Real-world oriented interface is a research field that aims to realize computers supporting our work in the real world. In our laboratory, we are working on the realization of real-world oriented interfaces.

Although computer performance continues to improve, a very long time is required to solve complex calculations such as deep learning, big data processing, and physics simulation. Therefore, we are researching to improve the computing performance of such complex and large-scale problems by parallel processing using GPUs and many-core CPUs.
Moreover, we are developing reconfigurable computing systems based on FPGA technologies and finding efficient computing algorithms with hardware/software co-processing.

I make a study on reliable, efficient and secure information transfer. In recent years, such as digital communication and digital recording device, it is increasingly digitized in a variety of systems. For improving the reliability of the digital system, error control coding technique is used. These areas of research is the field called coding theory. Error control coding techniques have been actually used in such as mobile phones, DVD, QR code, digital TV broadcasting. Decoding methods suitable for hardware implementation for low density parity check codes, and efficient coding methods for digital storage device such as flash memory are studied. we evaluate the performance by computer simulation.

In recent years, almost all digital systems have operated in synchronization with the clock pulse. However, high-frequency clock pulses not only increase the power consumption but also cause instability in the system. In our laboratory, we are working on the applications of an asynchronous circuit without clock pulses, for example, improving the performance of large-scale digital systems and reducing the power consumption of biometric signal processors. The proposed architectures are designed and implemented in the reconfigurable programmable gate array (FPGA), and we are also working on the FPGA-based image processing accelerator for surveillance camera systems and medical diagnostic imaging systems.

We propose a high-performance computer system called a Hybrid-Cluster and are conducting applied research. It provides a common framework for easy cooperation between computers and consumer electronic devices, such as controlling consumer electronic devices from computers and vice versa. In addition, in the field of educational technology, we are working on practical education, such as efforts to increase students’ self-study time and team development of software in lectures.