Masashi Miura

There is presently much interest in tunable, flexible, or reconfigurable metamaterial structures that work in the terahertz frequency range. They can be useful for a range of applications, including spectroscopy, sensing, imaging, and communications. Various methods based on microelectromechanical systems have been used for fabricating terahertz metamaterials, but they typically require high-cost facilities and involve a number of time-consuming and intricate processes. Here, we demonstrate a simple, robust, and cost-effective method for fabricating flexible and stackable multiresonant terahertz metamaterials, using silver nanoparticle inkjet printing. Using this method, we designed and fabricated two arrays of split-ring resonators (SRRs) having different resonant frequencies on separate sheets of paper and then combined the two arrays by stacking. Through terahertz time-domain spectroscopy, we observed resonances at the frequencies expected for the individual SRR arrays as well as at a new frequency due to coupling between the two SRR arrays.

We are developing a wireless sensor network system to monitor natural water quality. Our wireless sensor network system consists of sensors for detecting water quality and systems for transferring detected data and handling power modules. Previously, we proposed a low cost buoy type sensor node to monitor lake water quality. We prototyped a single sensor node and evaluated it in the lake. However, to obtain extensive field data for large-area lake water, multiple sensor nodes are necessary. In this paper, we report the improvement results of the previous sensor node, which is performed to achieve multiple sensor nodes as elements of the wireless sensor network system. The improved sensor node has compact size and the communication system of it is optimized. We fabricated the improved sensor nodes and evaluated them in the lake. As a result, we could confirm that the wireless sensor network system consisted of improved sensor nodes was successfully functioned in real time and real environment.

Use of a rotor type UAV that can perform three-dimensional movement and hover is being actively pursued. Although a multi-rotor type UAV is important, because it is driven by electric motors its application has the limitation of a short cruising time. In this study, the composition and control system of a single rotor UAV that achieves attitude control by pivotable vertical fins are proposed. Herein, the results of the dynamical simulations and experiments using a bread board model of the proposed UAV are described.

Demand response (DR) is one of the most promising solutions to efficient control of smart grids with renewable energy resources. Usually, DR programs are implemented by means of centralized control by power supply companies or independent system operators. In contrast, recently, the focus has been on decentralized control to enhance the efficient use of distributed energy resources especially on microgrids. This paper proposes a decentralized control system for DR. The key of the proposed method is a new decentralized algorithm for determining appropriate control signals (corresponding to prices and/or incentives) by using communication networks provided by smart meters. The effectiveness of the proposed method is illustrated by a numerical example.

We have been developing a wireless sensor network system to monitor the quality of lake water in real time. It consists of a sensor module and a system module, which includes communication and power modules. We have focused on pH, turbidity and chlorophyll a concentration as the criteria for qualifying lake water quality. These parameters will be detected by a microfluidic device based sensor module embedded in the wireless sensor network system. In order to detect the turbidity and the chlorophyll a concentration simultaneously, we propose a simple optical measurement method using LED and photodiode in this paper. Before integrating a turbidity and chlorophyll a concentration sensor into the microfluidic device based pH sensor, we performed feasibility studies such as confirmation of the working principle and experiments using environmental water samples. As a result, we successfully verified our simultaneous sensing method by using a simple optical setup of the turbidity and the chlorophyll a concentration.

We examine a feasibility study on multi-agent simulation for Hotelling model and then propose the prototype. Hotelling model is a theory that explains the consequence of the location competition of two sellers by analytically solving optimization problems in game situations. This model is employed to explain little product differentiation and agglomeration of retail shops. By introducing agent-based modeling and simulation, we could model complex situations which analytical approach can't explain. In particular, it will be widely applicable a relationship between change of consumer preference due to time change and seller's repositioning, and shopping vulnerable as an interaction of consumers and retailers.

This paper deals with a distributed constraint optimization problem on networked multi agent systems. First, we propose a distributed algorithm based, on the Lagrangian method, where a new update law of the Lagrangian multiplier is designed. This update law enables each agent to estimate the value of the Lagrangian multiplier in a distributed manner. Next, we derive a necessary and sufficient condition that the optimization problem is solvable in a distributed manner over a graph. Finally, we apply the proposed method to power grid control via distributed pricing to maintain the supply-demand balance. (C) 2016 Elsevier Inc. All rights reserved.

<p>This research aims to develop a web application to realize open model-based collaboration (Open MBC), which is a framework to support efficient and collaborative development of complex systems. We describe the concept of Open MBC and the features of the web application. Furthermore, we introduce an actual case, presenting requirements analysis and management to use the application in the CubeSat project at Osaka Prefecture University. Feedback from students described the difficulty of systems engineering and functional weaknesses prevented the use of our application. Based on this feedback, the paper proposes improvements to functions and operation methods. </p>

We demonstrate a simple and cost-effective method for fabricating silver-nanoparticle metamaterial structures on a flexible substrate based on inkjet printing. Specifically, we used inkjet printing with an ordinary printer to obtain an array of split-ring resonators (SRRs) on a sheet of paper. We designed the SRR array to exhibit a resonance in the THz region, which we observed through THz time-domain spectroscopy. We achieved good agreement between designed and measured THz transmission spectra for x- and y-polarized incident waves. In the measurement, we obtained the resonant frequencies of 0.305 THz and 0.137 THz for x- and y-polarized incident waves, respectively.

We have developing a wireless sensor network system for water quality monitoring. It consists of various sensors for the sensing of physical and chemical properties of water, and systems including wireless communication module, power module and interface between sensors and wireless communication module. In this paper, we report the development results of a novel wireless sensor network platform for water quality monitoring, which is proposed for rapid prototyping of wireless sensor network system. In order to demonstrate our novel wireless sensor network platform, we fabricated the platform as a sensor node and field-tested it with several sensors in the lake. As a result, we could confirm that our proposed novel platform was operated successfully in real environment.

With growing great interest in the energy problems, real-time pricing (RTP) for power systems has attracted attention in the world. In our research, a new distributed optimization method is proposed for RTP. It is based on negotiations between players (consumers, suppliers and distributors) through information networks. Then we developed a graphical and scalable multi-agent simulator for RTP which is named “RTPsim” for further investigations. RTPsim enables us to conduct numerical simulations in various conditions and various scales. This paper shows the new distributed optimization method based on negotiations, the features of our graphical and scalable RTP simulator and examples of simulation results.

In smart grids, Real-Time Pricing (RTP) is one of the most promising solutions for stabilizing power systems suffering from electricity shortage. RTP controls and time-shifts customer demand by adjusting electricity prices every moment. Normally, we assume the existence of Independent System Operators (ISOs) which determine the prices. Some countries have established ISOs to control their power systems. However, still many countries do not adopt ISOs, but they are discussing the necessity of ISOs. The main objective of this paper is to show that ISOs are not necessarily required to implement RTP programs. Actually, a new pricing algorithm is proposed which determines appropriate prices through negotiations between players (consumers, suppliers and distributors) through computer networks. This algorithm is mathematically rigid because it is based on an optimization method. We show that players can obtain appropriate prices without ISOs via distributed negotiations which stabilize the power systems.

© American Society for Engineering Education, 2015. Engineering is a fast-growing profession and is increasingly cutting across boundaries of disciplines, countries, and cultures and engineering education has to prepare students for these scenarios. Towards that, we organized an Indo Japanese program involving two student projects. The students and projects were from different engineering and non-engineering disciplines. This paper presents one of them - a water rocket project. Both the teams worked together for about four months and had enriching experience. The project had three parts: fabrication of water rockets, design and development of sensor systems, and analysis of the launches. Both the teams worked collaboratively on the activities. Initially, the teams worked from their respective locations and towards the end of the project, the Japanese team visited India for a week to fabricate water rockets, test sensor systems, and carry out and analyze actual launches. While the participants cherished this inter-cultural experience and gave a satisfaction rating of 4.82 on the 5 point Likert scale, they felt that they should have spent more time preparing for the visit, for learning the other language and establishing better communication with their counterparts. Even though the water rocket was a novel idea and resulted in substantial technical learning, the cultural learning was more significant. It may be due to the project's shorter duration and the significant divergence between the two cultures at syntactical levels.

Complexity science is a new field of science that help us to understand complex social phenomenon such as economies, traffics, wars, epidemics, mass actions, etc. On the other hand, multi-agents simulation (MAS) methods are useful and powerful tools for complex system science. They come to be applied to studies and analysis of complex systems along with the development of computers. It can be said that the perspectives of complex systems and the skills for MAS are very useful knowledge for students who should live and work in the complex modern society. Then the author tried to design and conduct an education program dealing with complex system science and MAS as liberal arts targeting at students from all faculties. It's a project-based learning program in which students investigated and discussed "What is complex systems?" and develop MAS. In general, it is difficult for students who haven't gained the any special knowledge of computing to build MAS. Then the author applied the generic multi-agent simulation platform "artisoc" to this program. With artisoc, students can build MAS easily. In this paper, the practical example of PBL program with artisoc and its result are introduced.

We are developing a wireless sensor network system for the lake water quality monitoring, which consists of sensor module, wireless transceiver module, control IC's and power module. In the sensor module, sensors to monitor the water quality such as pH sensor, turbidity sensor, chlorophyll concentration sensor and dissolved oxygen concentration sensor, will be integrated as a microfluidic device. The power module of a sensor node of the wireless sensor network system will be implemented with solar cells and thermoelectric effect based energy harvesting devices utilizing temperature difference between the surface and the bottom water layer. In this paper, we report the feasibility study results of a turbidity sensor that will be integrated into the sensor module for the lake water quality monitoring. Our turbidity sensor has been achieved by a simple optical setup, which consists of LED and photodiode. The turbidity is determined by measuring the transmittance of scattered LED light by the particles in the water sample. As a result of experiments with the lake water sample, we could verify that our simple optical measurement setup can be a useful tool in turbidity sensing.

In higher education, education of generic skills draws attention. Generic skills are fundamental skills indispensable for Innovation Education with real society. Nevertheless, as teaching and evaluation methods of generic skills are not clear, we developed a new framework for basic education program. In this study, we propose a framework of basic Monozukuri education program for generic skills. We suggest we could provide common experience of problem solving in a plurality of classes, and we could evaluate learners&rsquo; attainments based on this framework.

In recent years, a strong need has emerged for innovations in space activities for realizing a sustainable society. The paper aims to support designs and developments of nano-satellites as complex system of systems, and proposes an innovative framework named as an open model-based collaboration (Open MBC) that combine model-based systems engineering and pull-request version management system. We describe the web application to realize Open MBC. Furthermore, we show the system model of CosMoz that was developed by student team at Osaka prefecture university.