We have developed a laser distributor for highly-accurate optical frequency transfer of optical lattice clocks. Each output has a phase stabilizer based on a Michelson interferometer with all-fiber architecture. Varying the optical path length in the residual uncontrolled optical path to introduce phase noises between output branches, we found the residual frequency transfer instability to be much smaller than the frequency instability of current optical lattice clocks. All fiber configuration provides robustness which allows optical lattice clocks to be used in wide range of applications not only in a laboratory, but also outside laboratory, for example, geodetic applications.

Laser-based remote sensing system (LRSS) for detecting defects of concrete lining has been developed. This system can move a central passage in Shin-kansen tunnel and detected the concrete defects. We have developed automatic positioning and focusing system of impact and detection lasers. It was confirmed that this system inspected concrete defects with remote and high speed and soundness could be judged.

The sinterability of ceramic tiles was evaluated using terahertz (THz) time-domain spectroscopy. The transmittance, complex refractive index, and reflectance of the ceramic tiles fired at various temperatures were measured in frequency range of 0.3-1.2THz. The relation between these THz properties and their sinterability were examined. The firing-temperature dependences of the refractive index and reflectance at 0.5THz showed a similar behavior as that shown by the bulk density. These results show that the THz spectroscopy can be applied to nondestructive inspection of the sinterability of ceramic tiles.

Ultrasonic wave generated by interaction of the material with pulsed lasers is known to photoacoustic (PA) wave. In this study, the PA imaging is applied to the nondestructive testing for carbon fiber reinforced plastic (CFRP). When subsurface flaws are in CFRP, the detection of the flaws is sometimes challenging because the trailing signal from the surface interferes with the scattered signal from the flaws. Here we developed a PA microscopy (PAM) to reconstruct the location and the shape of the subsurface flaws. The PAM employs a confocal arrangement of optical and acoustic lens to maximize the intensity of generated PA waves. To enhance the lateral resolution of the image, we introduced the synthetic aperture focusing technique (SAFT). In the SAFT, it is necessary to consider direction-dependent group velocities due to the strong anisotropy in CFRP. The performance of the PA imaging combined with the SAFT was checked with artificial delaminations in a cross-ply CFRP specimen. It was shown that the PA wave had a wide frequency band and our method offered a high spatial resolution image.

Terahertz (THz) wave has both of characteristics as represented by transparency of radio wave to non-polarized substance and good reflectivity to metal of light wave. Our group has created a database of THz permeability characteristics for industrial materials, and successfully constructed non-destructive THz diagnosis of building blocks, insulated copper cable.

It is important to understand the relationship between spatiotemporal patterns of neuronal populations and information processing of the brain for medical and engineering purposes. Though, there are some methods to record neuronal population, only the information about firing rate can be obtained from those methods basically. Therefore, some methods are suggested to estimate the internal state of the neuronal population from the information about firing. In this research, we investigated the relationship between firing rates and responses to external electrical stimuli by using neuronal population models. We developed a method to manipulate neuronal parameters to make neuronal populations exhibit different dynamical properties while keeping firing rates intact. As a result, we found that there are some cases even though they share the same firing rate, the internal states are different. This result suggests that there is some information that cannot be obtained by using only the information about firing rates.

There is a growing need to use photovoltaic (PV) technology to mitigate global warming and the depletion of fossil fuels. However, the high network penetration of PVs potentially lessen the stability and the reliability of electrical power systems in various ways. Under its high network penetration, monitoring of the unmeasurable power outputs of PVs is needed for the proper operations of an electrical power system. To suffice this need, a novel method was proposed to estimate the PV power output of the system using the measured power flow and sampled PV power output data in our previous work. However, the large estimation error of the PV power output caused by the wrong estimation of a parameter occurs occasionally in the proposed method. Thus, in this paper, we improved our proposed method by calculating the average value of the estimated parameter and confirmed its accuracy enhancement using observed data from The Kansai Electric Power Co., Inc.

In recent years, there is an increment in the development of applications that have the purpose of supporting people in diverse situations. Our research focus is on the development of an application that will contribute to an effective community self-relief in case of disaster. In this specific area, software developers should propose easy to use and easy to understand interfaces. For that reason, we propose the design of a front-end application that uses animated and non-animated pictograms as graphical communication for an understandable interface. The animation of the pictograms was possible by the addition of simple animation patterns. In this study, we included the examination of the understanding effect of each pictogram by subjects with different cultural backgrounds. Additionally, we performed a comparison between the animated and non-animated pictograms. With this examination, we intend to identify a possible increment or change in each pictograms' degree of understanding. After the validation process, it is possible to determine the viability of using these pictograms in our user-front application.

In this paper, we consider position estimation by Finger Print method using RSSI of wireless LAN access point. Although it is highly accurate indoors, it is week to change in the environment and it is necessary to periodically update the database. Therefore, RSSI approximate expression is created from a part of measurement data and coordinate information, and an RSSI of other coordinates is created. This aims to reduce the number of measured coordinates. In this paper, it was confirmed that the estimation accuracy equivalent to the database measured at intervals of 3.6 m can be obtained by measuring at 7.2 m intervals.

In this paper, we conducted a subjective experiment in order to investigate that the naturalness of vibrato of singing voice is affected by fine fluctuation and global fluctuation. In this subjective experiment, listeners judged the naturalness of synthetic sounds with vibrato having fine fluctuation and global fluctuation or not having these fluctuations. It can be clarified that the cosine wave instead of a signal having fine fluctuation and global fluctuation can be used as a vibrato signal, because the naturalness of vibrato is not affected by these fluctuations.