Our two-degree-of-freedom helicopter apparatus is a nonlinear and multiple-input multiple-output system. Therefore, it is difficult to design the controller which guarantees the desired performance in the wide range. In this paper, we design I-PD controller based on the DE (differential evolution) method, which is one of evolutionary computing algorithms, in consideration of the nonlinearity and the cross coupling. Finally, the validity of our designing method is shown through some experiments.
Main objective of this study is to examine simplication of electromagnetic measurement in ELFVLF band to monitor thunderstorm activity. To detect lightning discharge, receivers in ELF-VLF band are installed with unprecedented density (about 30 km apart) to make detection sensitivity to be high. To reduce data size, sampling rate of our electromagnetic measurement is set as 100 kHz, which is relatively lower than that of recent lightning observation to monitor thunderstorm activity, and precision of geolocation becomes about 10 km. Additionally, electrostatic field is also measured to monitor temporal variation of charge separation and discharge in cloud. In this paper, observation result of thundercloud above Ebina City, Kanagawa, Japan on September 6th, 2014 is summarized. Initial result indicates that charge and discharge in cloud at the early stages of isolated thunderstorm could be detected by using radio observation in ELF-VLF band and electrostatic measurement. This result indicates that electromagnetic measurement in ELF-VLF band, which has been traditionally designed to monitor lightning activity on a synoptic scale, can be utilized to monitor thunderstorm whose horizontal scale is about 10 km and to decrease cost of lightning observation substantially.
Although there are a lot of opportunities to have a multi-party conversation such as decisionmaking meeting and brainstorming, we do not always have a good communication. In multi-party conversation, it sometimes ends up as one-way conversation because of someone's too much speaking, and people cannot understand a less-speaking person's thought. Considering the situations where a balanced participation is desirable, the amount of speaking time should be well controlled. We propose a co-located meeting support system called ScoringTalk that activates conversation by visualizing conversation state in real-time, providing scores based on the amount of conversation, and facilitating participant's behavior such as speaking, listening, and changing a conversation partner to make a balanced conversation. In ScoringTalk, each participant has a tablet with dual camera, and it works as both sensor and display. Tablets are commonly used in social meetings, therefore, there are no need to prepare projectors and microphones. The evaluation result showed that our system measured conversation, provided the visualization of conversation, scores, and facilitation, and increased the balance of participation while keeping the amount of speaking time.
Photovoltaic (PV) generation has experienced the most growth among the renewable energy sources in the last few years, and the interconnection capacity of PV generations may continue to increase. However, more recently, the capacity of qualified PV generation facilities exceeds the allowable interconnection capacity determined by each power grid company. This fact is recognized as a critical issue for reliable operations of power grids, and it will be enforced by law that the power gird company can announce the output suppression instruction signal to the PV generation plants. An output suppression essentially means wasting potential solar energy. Operating methodologies for the PV generation plant that can reduce the amount of wasted energy are needed to be developed. This paper considers the PV generation plant equipped with the energy storage and investigates decentralized management of power conditioning systems which are used to interconnect the PV system into the grid. The proposed decentralized management methodology can attain the assigned output power as well as reduce the amount of wasted energy.