We have developed a total-power radiometer to establish a noise standard for the national metrology standards in the frequency range of 18-26.5 GHz. The radiometer is based on the heterodyne scheme working on the intermediate frequency (IF) of 30 MHz. The IF signal is detected by null-balance method under the control of the IF variable attenuator. The RF noise temperature can be determined from the attenuation after the balance, since the RF noise power is proportional to the attenuation. We have investigated the uncertainty sources of the radiometer, such as stability, non-linearity, internal noise parameter and Y factor defined as the ratio of the measured noise power levels, and quantitatively evaluated each contribution by the sources. To improve the uncertainty of the Y factor that is one of the major uncertainty, we have adopted an accurate calibration method of the IF attenuator by directly comparing it to a precision step-attenuator calibrated by the national standard of attenuation. As a result, the type B combined standard uncertainty of the radiometer was estimated to be less than 1 % in the noise temperature range from 300 K to 30000 K.

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In the situation in which a robot and a human work together by collaborating with each other, a robot and a human share one working environment, and each interferes in each other. The boundary of each complex dynamic occupation area changes in the connection movement which is the component of collaborative works at this time. The main restraint condition which relates to the robustness of that connection movement is each physical charactristics, that is, the embodiment. A robot body is variability though the embodiment of a human is almost fixed. Therefore, the safe and the robust connection movement is brought when a robot has the robot body which is well suitable for the embodiment of a human. A purpose for this research is that the colaboration works between the self-reconfiguration robot and a human is realized. To achieve this purpose, sensing function of external environment on a module was examined. A module is a component of the self-reconfiguration robot. A robot body vibrates when a module actuates an arm actively. This vibration is observed by using some acceleration sensors. Measured datas reflects a difference of objects that it touches a robot body. In this paper, the sensing technique of external environment which identifies this difference by using the neural network is proposed.

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Recently, some professional whistlers have set up music schools that teach musical whistling. Similar to singing, in musical whistling, the whistling sound should not be break, even when the whistling goes on for more than 3 min. For this, it is advisable to practice whistling the “Pii” sound, which involves whistling the “Pii” sound continuously 100 times with the same pitch. However, when practicing alone, a whistler finds it difficult to count his/her own whistling sounds.
In this paper, we propose a whistling sound counter based on piezoelectric bone conduction. This system consists of five parts. The gain of the amplifier section of this counter is variable, and the center frequency (f₀) of the BPF part is also variable. In this study, we developed a prototype of the system and tested it. For this, we simultaneously counted the whistling sounds of nine people using the proposed system. The proposed system showed a good performance in a noisy environment.
We also propose an examination system for awarding grades in musical whistling, which enforces the license examination in musical whistling on the personal computer. The proposed system can be used to administer the 5th grade exam for musical whistling.

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Structural health monitoring systems have recently been researched and developed to ascertain the scale, danger level and location of structural damage in order to protect the lives of people from disasters caused by damage to artificial structures such as bridges and from natural disasters such as bedrock collapse. We are involved in a project to construct a wide-area structural health monitoring system using a multi-point fiber Bragg grating (FBG) with optical frequency domain reflectometry (OFDR). This system incorporates multi-point FBGs with the same reflection wavelength, and multi-point FBGs with different reflection wavelengths. By using an optical micro-electro-mechanical systems (MEMS) switch to multiplex these FBGs together, we showed that the reflected wavelengths can be measured in real time. This system is capable of monitoring the reflected wavelength measurement status of the selected channel every 4 seconds (corresponding to the period of the optical frequency sweep). By sequentially switching the optical MEMS switch, it is possible to monitor the time-series variation of reflected wavelengths of all channels. By using this system to perform continuous measurements over a 24-hour period, we also demonstrated the feasibility of performing static strain distribution measurements over a long period.

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We propose a new passively mode-locked fiber laser (MLFL) for an optical quality monitor that we developed based on all-optical sampling technology. With conventional passively MLFLs, the repetition frequency of optical pulse cannot vary arbitrarily. The repetition frequency of proposed laser can be changed around center frequency by temperature control. This paper shows configuration of this laser and experimental results of temperature drift and repetition frequency linearity.

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We observed sea clutter using an X-band Radar in some area of Tokyo Bay including ships on the Uraga Suido traffic route and the Daini Kaiho sea fort, and furthermore observed the sea condition. By analyzing the observed data statistically, we studied the effect of the sea condition for the statistical properties of the sea clutter. As a result, we showed that the sea clutter in case of including no target obeyed the Weibull distribution but that in case of including target tended to obey the Log-Weibull distribution or Log-normal distribution. And also we showed that correlation between the shape parameters c of Weibull distribution, Log-Weibull distribution and the significant wave height were strong. In addition, we showed that there was no correlation not only between the wave period and the shape parameter c of Weibull distribution, but also between the wave period and the shape parameter c of Log-Weibull distribution.

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The passing on and preserving of advanced technical skills has become an important issue in a variety of fields, and motion analysis using motion capture has recently become popular in the research of advanced physical skills. This research aims to construct a system having a high on-site instructional effect on dancers learning Nihon Buyo, a traditional dance in Japan, and to classify Nihon Buyo dancing according to style, school, and dancer's proficiency by motion analysis. We have been able to study motion analysis systems for teaching Nihon Buyo now that body-motion data can be digitized and stored by motion capture systems using high-performance computers. Thus, with the aim of developing a user-friendly instruction-support system, we have constructed a motion analysis system that displays a dancer's time series of body motions and center of gravity for instructional purposes. In this paper, we outline this instructional motion analysis system based on three-dimensional position data obtained by motion capture. We also describe motion analysis that we performed based on center-of-gravity data obtained by this system and motion analysis focusing on school and age group using this system.

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The dielectric is one of important materials in electric devices. To evaluate the permittivity of the material in high radio frequency range, several practical measurement systems have been developed. The scattered method proposed in this paper can easily estimate the permittivity of a dielectric whose size can be small in comparison to the wavelength. The relationship between the scattered field strength and the permittivity of the dielectric scatterer is theoretically analyzed, and the formulation is denoted quantitatively. Additionally, the polarizability of a cube and a cylinder was investigated to compensate for the effects shape of the specimen might have. Their compensation factors to the value of a spherical were calculated to be less than 30% larger. Moreover, a frequency domain method detecting the phase shift of the scattered wave caused by the polarization delay was studied to estimate dielectric loss.

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A practical technique to apply the mismatch loss correction in radio frequency (RF) attenuation measurements of fixed attenuators as well as variable attenuators as devices under test is presented. The correction factor is obtained by measuring the reflection coefficients of the source and load testing ports, and the devices under test using a vector network analyzer. The formula to express the residual uncertainty of this correction is derived by implementing the law of error propagation after modifying the general mismatch loss equation. The solution is also given; hence the uncertainty of the obtained mismatch correction is simply estimated and used. Experimental results on a 10-dB step attenuator measurements at frequencies of 1 GHz to 18 GHz show good agreement with measurements where the source and load are impedance matched.

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The electric power is indispensable for modern life. However, there is a problem of harmonic disturbance when the harmonic power runs into electronic devices. To overcome the problem and realize a stable supply of the electric power is an important issue. In this study, we have developed a voltage-current waveform telemetry system for the remote measurement of the harmonics in the power delivery lines. The system consists of sensors, preamplifiers, a single board computer, and power collectors. Improvements are made on all of these components except the sensors. The power collector is a coil that can be placed around the same power line that we measure. We have designed the power collector by a finite element method(FEM) so that it can provide enough electricity for the computer to work properly. Thus, no other power source such as a battery except the secondary rechargeable battery for the recovery is necessary at the measurement place. The preamplifier in the new system is a single-supply differential amplifier circuit, and the single board computer has an inexpensive SH-3 CPU. Through experiments, we have confirmed that the power collector can provide sufficient electricity and that the new system can successfully measure the waveforms and the harmonics in power delivery systems.

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We propose a new multimodal tactile sensor for identification of objects. The proposed sensor integrates measurements of permittivity and optical reflectance by capacitance electrodes in a pair of CdS cells, electrical measurement of object stiffness, and contact voltage measurement into a single unit. Using this multimodal sensor, nine objects with different material properties (permittivity, reflectance, stiffness and contact voltage) can be identified. The proposed sensor may be applicable for a tactile sensor in robots.

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We have experimentally evaluated the equivalent noise temperature (ENT) of a microwave standard noise source. The resistivity and its temperature coefficient of a transmission line (TL) of the noise source were determined by the curve fitting technique based on the TL theory. As a result, the ENT was estimated as 133.3-144.4 K in the frequency range of 0.01-18 GHz.

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We studied a variable noise source using a precision variable attenuator in the frequency range of 50 - 75 GHz, and its uncertainty was analyzed in detail. To determine the noise temperature of the noise source, the variable attenuator was calibrated by the national standard of attenuation in NMIJ. It was proved that the contribution of uncertainty concerning the variable attenuator was considerably small by achieving its precise calibration. This variable noise source can be used as a working standard for the millimeter-wave noise figure measurement.

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Humanity fluctuation was reported in some fields. In handwriting process, fluctuation appears on handwriting-velocity. In this report, we focused attention on human rhythm perception and analyzed fluctuation in handwriting process. As a result, 1/f noise related to rhythm perception and features may caused by Kahneman's capacity model were measured on handwriting process.

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