[in Japanese]

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In order to fulfill the strong demands for the clean electric energy sources, much effort has been devoted to develop photocells with non-traditional materials, encouraging the researchers who have been mainly working on chemistry or materials science to be involved into the photocell study. The spectral response is one of the critically important characteristics of photocells, especially for those using newly developed materials. However, traditional apparatuses for the spectral response measurement, which usually consist of a white light source such as Xe-lamp and monochromator, are expensive for the newcomers in this field. In this context, we report here the prototyping of a simple device for the measurement of spectral response of photocells using LEDs. It is confirmed that the prototyped LED-based device can reasonably reproduce the spectral feature of the sensitivity of a photocell based on GaAsP.

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Rate-distortion optimized quantization (RDOQ) is an important technology in H. 264/AVC for improving video coding performance. RDOQ is able to determine the optimal value among multiple quantization candidates based on rate-distortion (RD). We propose improvements to the algorithm to reduce its complexity by changing the bit-rate estimation method and by excluding low scored quantization candidates. We also implement the algorithm in hardware using the Bach C high-level synthesis tool. Finally, the performances of the proposed algorithm and hardware design results are evaluated.

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We fabricated 1 STEP biomarker protein analysis device using silver nanoparticle (AgNPs)-contained hydrogel and reagent immobilized cartridge. Specific color change of AgNPs based on localized surface plasmon resonance (LSPR) was applied to develop the novel colorimetric protein analysis device. In this report, we constructed this device by 4 components, AgNPs-contained hydrogel, Glucose oxidase (GOx) release pad, Glucose release pad, and Antibody immobilized membrane. AgNPs-contained hydrogel detected 0.001∼10 µg/mL GOx-antibody. AgNPs-contained hydrogel absorbance became altered 90.0% GOx release pad as compared to GOx-antibody solution under the reaction time 60 min. AgNPs-contained hydrogel absorbance became altered 98.4% Glucose release pad as compared to glucose solution under the reaction time 60 min. We applied AgNPs-contained hydrogel and Antibody immobilized membrane to detect Human immunoglobulin G (IgG). As a result, we found these could detect 1 µg /mL or lower concentration of Human IgG.

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Hand motion capture is an important topic for understanding the mechanism of the hand. General hand motion capture methods using cameras or bending sensors can capture the limited action in the restricted environments. This study proposes a novel hand motion capture method without restrictions of usage environment and user's action. The proposed method is based on the electrical contact resistance between the wrist skin and the electrode to measure the deformation of the wrist which is related to the hand motion. We fabricate the contact resistance measurement circuit consists of 3 electrodes and a multiplexer. The output voltage corresponding to each contact resistance of the electrode is measured with the circuit by switching the active electrode temporally. We confirm that the output voltage is related to the wrist shape and changes according to the hand posture. Furthermore, the result suggests that the finger joint angles can be estimated from the output voltage due to the correlation between them.

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The aim of this study is to analyse the mechanism of tongue movement in an infant during sucking. We directly measured the force applied on an artificial nipple using small built-in force sensors. Force sensors are cantilever structures with a thin stainless steel beam and an all-purpose foil strain gauge attached to the surface of the beam. The sensors are arranged at the tip, middle and base of the nipple to capture velocity of the tongue elevation. The signal, obtained from the force sensor running through a bridge circuit and amplifier, is A/D converted with a sampling frequency of 1kHz, and a 12bit quantization resolution is input to the PC via a USB port. The measurement data are displayed in a real-time graph on a monitor. Using this system, we continuously measured the force applied on an artificial nipple during effective and ineffective sucking in infants. We found differences between infants with and without established oral feeding with respect to phase difference and the maximum force applied to the nipple. Furthermore, the velocity of the tongue movement was calculated and showed differences between individual infants.

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Hand sign recognition is one of most challenging tasks in some research area. In this research, we focus on JSL (Japanese sign language). Although many hand sign recognition methods with depth sensor have already been proposed and they have achieved high accuracy, they have a problem such as the requirement that signer wears a color belt on the gesturing hand to extract a hand region precisely. Therefore we consider that there is still a room of improving the HRE (hand region extraction). In this paper, we propose a new automatic HRE method using a depth sensor and Time-Series Curve, which is one of contour features. Additionally, in the conventional SVM-based methods, brute-force matching of hand signs is applied for achieving high recognition performance. However, this process is required long processing time. To solve this problem, we focus on the FD (finger direction) of JSL. In this paper, we propose a new FD recognition method for effectively restricting the number of target signs in the recognition process. From the experimental results with 8 subjects, we have achieved the similar HRE accuracy compared with the conventional method without wearing a color belt and 96.5% of recognition rate of FD.

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In the Decision Support Method with AHP, each evaluation criteria are evaluated for target objective, and each alternative are evaluated for each evaluation criteria. This method recommends alternatives to the user according to the total degrees of weight, which is calculated from these two kinds of evaluation values. If the target user does not know all alternatives, AHP needs to use the average value of other evaluators’ evaluation in usual decision support method. However, this method does not reflect target user’s preference, and the result does not satisfy the user in many cases. This paper proposes a decision support method with AHP according to similar preference. The proposal method searches the set of alternatives evaluation by others, which is nearest to evaluation by target user in the evaluation distance between alternatives. Evaluation distance is calculated using the value of an evaluation level. The shorter distance the set of alternatives is, the more appropriate alternatives user finds in this method. In practical experiment, the proposal method recommended more satisfied alternatives than the usual method, in which the evaluation value of alternatives is the average value among other evaluator.

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This research considers a short-range communication system using smartphones for when wireless communication lines are down. Acoustic communication technology is used for exchanging information in this system. That technology does not require any special device features other than speakers and a microphone. A fundamental investigation into the effectiveness of the proposed method is carried out in this research.

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In order to distinguish the point where an optical fiber cable is deteriorated, estimation technique focused on the difference of daily change of optical loss is proposed. At degraded section of a cable, included optical fiber is bent by the neighboring parts and optical loss at the portion is changed daily by shrinkage and expansion of them. Therefore deteriorated part is able to be detected by comparing the extent of the alteration of optical loss of each section from OTDR measurements. Effectiveness of the scheme is evaluated by experiments using aged OPGW's installed in the field.

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The acoustic distance measurement(ADM) method based on phase interference has been proposed. However, it becomes difficult for ADM to measure the distance to target shorter than distance resolution. Though the principled method for close range has been also proposed by introducing analytic signal, the measurement performance was degraded by the DC component of the power spectrum. This paper describes a new trail on the ADM with 2ch microphones for very close range measurement by estimating and removing the DC component.

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The transmission performance of a digital power line carrier system with adaptive equalizer degrades in the presence of the carrier frequency offset (CFO). Therefore, accurate CFO estimation and compensation is necessary. In this paper, we propose a CFO estimation method suitable for a digital power line carrier system with adaptive equalizer in the presence of delayed propagation paths. The proposed CFO estimation method estimates the CFO from the measured phase rotation per symbol which is obtained by the measurement of autocorrelation of a 4PSK training sequence. By setting the time separation for autocorrelation measurement to the training sequence length, the accurate CFO estimation is achieved in the presence of delayed propagation paths. In order to achieve sufficiently accurate CFO estimation in a low SNR condition, averaging the instantaneous autocorrelation measurements is done by a simple first-order filter. It was confirmed by computer simulation that even in the presence of delayed propagation paths, by using the proposed CFO estimation method, a digital power line carrier system with adaptive equalizer achieves a BER performance close to the case of no CFO.

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We have suggested the combination use of Amplitude Difference Index Ring Filter (ADR) and Positive Convergence Index Ring Filter (PCR), for the first step processing of extraction of the pulmonary nodules. Applying those two filters whose behavior is different is effective for extracting nodules. In this study, we applied those two filters and the classification method for reduction of false positive based on the local average similarities of k-Nearest-Neighbor patterns in individual categories to LIDC. The result showed that those 3D methods are effective for extraction of the nodule in thin slice chest CT, the same as in thick one.

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Patients with mild cognitive impairment (MCI) and healthy people were classified by using “Power variance function (PVF)” of electroencephalography (EEG) recorded on only 4 electrodes in this study. PVF is an index of power variability of EEG proposed in a previous report. In this study, the balance of PVFs on a head of each person was analyzed. EEG signals of 25 MCI patients and those of 57 healthy people were recorded on Twenty-one electrodes in accordance with the 10-20 International System while the patients were at rest with eyes closed for 5 minutes. After noise reduction, the balance of PVFs of the MCI patients and those of the healthy people were compared. The results indicated that for MCI patients, the difference between PVFs of the frontal region and those of the occipital region was significantly smaller than that of healthy people in theta-alpha band. Moreover, it was found that the balance of PVFs were especially different between MCI patients and healthy people in theta-alpha band on 4 electrodes (O1, F3, Fz, and Cz as the reference). These electrodes were, therefore, selected for classification of MCI patients and healthy people. As the classification result, accuracy of 89.0%, sensitivity of 84.0%, and specificity of 91.2% were achieved.

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We have been developing a pneumatic total artificial heart (PTAH) system which was driven by a wearable pneumatic drive unit (WPD). The WPD which have driven one blood pump by one actuator, called as WPD100, had problems such as high power consumption, large size and excessive negative air pressure. To solve these problems, we developed a WPD twin head type (WPD TH) equipped with a mechanism to drive two pumps by one actuator and relief valves to avoid excessive negative pressure. In this study, we evaluated the performance and characteristics of the WPD TH in a mock circulation test and numerical calculation. As a result, the maximum flow rates of the left and right pumps driven by the WPD TH were 7.9 L/min and 9.3 L/min even under the pressure release in diastole. The maximum power consumption and the efficiency were 27.6 W and 6.6% in the case of right and left pumps driven from side to side, and these were improved in comparison with WPD100. The alternate drive method had advantages of suppressing vibration and a mechanical load in the numerical calculation. These results indicated that the WPD TH had a basic performance to realize a wearable PTAH system.

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An automatic control on the GHTA (Gas Hollow Tungsten Arc) welding has been required to weld with safety and accuracy in the space. And a technique that uses a relationship between gradation value of infrared rays from entire state in the welding including an arc and a molten pool (hereinafter referred to as “average brightness value”) and a bead width was suggested for the automatic control on the GHTA welding. In this study, a welding speed control using the infrared images in the GHTA welding was carried out to maintain the bead width constant. The welding speed was proportional controlled, and a CCD camera was used to film the welding sate. As a result, the bead width was kept constant by the automatic control of the welding speed.

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In this paper, we propose a new technique for a measurement of crank angle in a real-time of an automobile engine application. In conventional method for the measurement of the encoder that mainly limited to a laboratory experiments, thus, it is impossible to obtain sufficient information including the effect of wind or variations of the torque that occurs when it has been implemented in the real vehicle. In this study, we use the crank position sensor in order to solve aforementioned problems in effective way; where the prediction and interpolation are necessary to realize in the real-time measurement. Prediction is possible to obtain sufficient accuracy by build an engine speed prediction model using the autoregressive moving average (ARMA) model that has been designed based on the measurement values of the past and current. Furthermore, an interpolation is possible to obtain a sufficient accuracy by reproducing the crank angular acceleration by a physical model using known information.

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This paper proposes a concept of the adaptive asynchronous human machine system (Async-HMS) which maintains asynchronous periodic operations against user's actions for avoiding user intention. In order to find the dynamics of the operation period presented by Async-HMS, discrimination thresholds of the operation period were obtained by psychophysical experiment. According to the thresholds, three levels of fluctuation of the operation period were defined as ‘constant’, ‘unrecognizable’, and ‘recognizable’. Psychophysiological measurement was conducted on the performance of the synchronized key typing task by the three levels of the operation period. A synchronization error as performance index, the hemodynamic parameters as indices of autonomic nervous system's activity, and the amount of the senses as psychological indices were evaluated. As a result, monotonous feeling was eliminated without compromising the performance in case of `unrecognizable' fluctuations in the operation period presented by Async-HMS.

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In this paper, we propose a boundary layer adaptation law for sliding mode control to suppress the chattering. The proposed method is more robust than conventional methods. To verify the advantages of the proposed method, we compared with the proposed method and conventional methods by simulations about the vehicle positioning control.

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In this paper, we propose a new systematic design method of a regularization parameter for L₁-norm minimization problem by using statistics of noise. We consider L₁ regularized linear regression andL₁ regularized logistic regression as the minimization and we analyze a relationship between their regularization parameters and system parameters. In the case of L₁ regularized linear regression, we show that a condition of the regularization parameter is given by LMI parameterized by a covariance matrix of measurement noise. Also in the case of L₁ regularized logistic regression, we show that the regularization parameter satisfies LMI described by a variance of a modeling error of a logistic model. Since the proposed design method requires a value of second moment of noise, we estimate the value by a sample covariance matrix. We demonstrate the effectiveness of the proposed method by numerical simulations, in which we use random systems and real data sets to evaluate the proposed method.

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In recent year, in order to pursue high functionality of the embedded systems, the function has been increasing and mechanism for concurrent executing functions has been required. System using a real-time operating system are building a concurrent processing using tasks, and high urgency processing and input/output processing are building using the interrupt processing. In this case, there is a possibility that the interrupt processing of low priority to inhibit the interrupt processing of high-priority. Therefore, we proposed an interrupt scheduler REMON(Real-Time Embedded Monitor), and we improved the real-time property of exclusive control of critical section between ISR when using multiple interrupts. REMON is implemented completely in software, but number of resources increases, there is a problem in the state trandition and search sequential processing load is increased. This paper describe the results of performance evaluation and proposal of HW(HardWare)-REMON. It is implementing in hardware scheduler to solve the above problems. By this function, when we have exclusive control to multiple interrupts, we were able to executed the switching of the ISR in two cycles.

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Bad posture while working on VDT (Visual Display Terminals)-based systems can cause negative effects, such as stoop. However, it is difficult to notice such negative effects on our own. This letter presents a system to determine the postures of workers using a 3D (three-dimensional) camera (Microsoft Kinect). Experimental results show that the system can determine particular postures.

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