Electromagnetic silicon MEMS resonator

We have fabricated a silicon MEMS resonator aiming at multimodal sensors, and evaluated vibration characteristics by electromagnetic drive and induced electromotive force detection. The resonance frequency of the driving voltage of 0.6 Vpp shows torsional vibration of approximately 87 kHz, and the resonance frequency is shifted toward the low‐frequency side as the driving voltage increases. Resonance characteristics due to temperature change and film stress were evaluated.     

Analysis of spatial smoothing effect of short‐term fluctuation of global solar radiation based on data including quantization error

Photovoltaic (PV) systems are attracting attention as one of the promising countermeasures against global warming and the environmental issues. However, the generation output from PV systems is generally unstable and unpredictable. Therefore, large penetration of PV systems may cause some serious impacts on power system operation, such as load frequency control, voltage regulation, etc. Estimation of the influences of PV system installation is becoming important, but it requires simultaneous multipoint solar radiation measurements. The Japan Meteorological Business Support Center has provided 1‐minute meteorological data observed in Japan, but its solar radiation data includes quantization errors. This paper proposes a regeneration method for solar radiation data including quantization errors. It also analyzes the spatial smoothing effect of global solar radiation fluctuations. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(3): 55–63, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21274     

Preparation of PZT Thin Films by Liquid-Source MOCVD Using of Cyclohexane Solvent

Pb(Zr, Ti)O₃ thin films were grown on 8-inch Ir(111)/SiO₂/Si substrate by a MOCVD system aiming at application utilizing high-density ferroelectric memory (FRAM). Two types of solvents, THF and cyclohexane were used for liquid source delivery. It was found that the ferroelectric properties of the MOCVD-PZT films using cyclohexane solvent were better than them using THF solvent. By choosing cyclohexane as solvent, the MOCVD-PZT thin films showed strong ?111? preferred orientation and the Pt/PZT/Ir capacitors exhibited promising ferroelectric performances, for instance, large switching charge (Qsw) of 56.4 uC/cm².     

Influence of electrode material on pressure‐rise due to arc in a closed chamber

This paper describes the phenomenon of internal pressure‐rise due to arcs ignited between metal rod electrodes in air. First, the internal pressure‐rises in a closed chamber due to arcs were measured at currents within the range of 1 to 12.5 kA. The rod electrodes were made of copper, iron, and aluminum, and were 20 mm in diameter. The measurements showed that the maximum pressure‐rise distinctly differed with each electrode material at the same total arc energy, namely, the maximum pressure‐rise was the highest in the case of the aluminum electrode and was the lowest in the case of the iron electrode. Next, to quantitatively verify this difference, the internal pressure‐rise was estimated, taking into account the energy balance in the closed chamber on each electrode material. It was found that the estimated pressure‐rise approximately agreed with the above experimental results by taking into consideration oxidation reactions of the electrodes, melting and vaporization of the electrodes, and radiation loss of the arcs under certain realistic assumptions. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 9–18, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21071     

Rule Construction and Execution for Root Cause Analysis

We developed a root cause analysis (RCA) system for an enterprise IT system environment. In this paper, we propose a rule‐construction method that builds analysis rule data objects from general analysis rules and the topology information of the actual target IT environment. Using this method, the IT administrator can use the RCA system without any manual rule modifications. For the execution of the analysis, we introduce the certainty factor to realize robust analysis when the order and reachability of a fault event cannot be guaranteed.     

Evaluation of Lysophospholipid Measurement in Cerebrospinal Fluid Samples using Liquid Chromatography–Tandem Mass Spectrometry

A quantification system for lysophospholipids (lysoPL) was developed, especially for blood samples, using liquid chromatography–tandem mass spectrometry (LC–MS/MS). However, the lysoPL measurement in cerebrospinal fluid (CSF) has not been validated. Therefore, the present study aimed to validate the lysoPL measurement using CSF samples and to elucidate the possible clinical significance of the lysoPL measurement in CSF. For the validation, we observed a good precision and linearity in a sample with high lysoPL levels. The concentrations of lysoPL changed after incubation but the changes were smaller than those observed for serum samples. Moreover, we observed that the CSF levels of 16:0, 18:0 lysophosphatidylcholine, and 18:0, 18:1, and 20:4 lysophosphatidic acid were significantly higher in subjects with central nervous system invasion caused by hematological malignancies or carcinoma than in subjects with no abnormal CSF test results. In conclusion, an LC–MS/MS quantification system for lysoPL in CSF might be useful and could be applied to clinical laboratory testing.     

Structure and mechanical properties of multi‐hollowed fibers produced by CO2 laser irradiated neck drawing

Multi‐hollowed fibers with a hollowness ratio of over 20% were successfully produced using a neck‐drawing technique accompanied by CO₂ laser irradiation on unoriented and amorphous polytrimethylene terephthalate (PTT) fibers with diameters of approximately 104 µm. The structure and mechanical properties of the multi‐hollowed fibers were characterized using scanning electron microscopy, wide angle X‐ray diffraction (WAXD), birefringence measurements, and tensile tests. Crystal orientation factors in the direction normal to the (010) and (002) planes, which were obtained from WAXD patterns, were lower in comparison to values obtained in previous studies on fibers that did not feature these hollows [9] because of the development of these internal hollows. The PTT fibers in this study also displayed high toughness, about 465 MPa (3.5 cN/dtex) strength and about 40% elongation, and had excellent elastic recovery (>95%) after 10 stretch cycles. POLYM. ENG. SCI., 56:609–616, 2016. © 2015 Society of Plastics Engineers     

Fully digital LCoS device for consumer applications

Abstract— This paper presents a new display device, which combines a digital backplane and a vertically aligned nematic liquid‐crystal layer. The device has 1280 × 720 pixels in a 0.7‐in.‐diagonal display area. In this paper, we present the concept of the new device and overview the performance of the device for a rear‐projection television application.     

Robot-vision architecture for real-time 6-DOF object localization

This paper presents a new robot-vision system architecture for real-time moving object localization. The 6-DOF (3 translation and 3 rotation) motion of the objects is detected and tracked accurately in clutter using a model-based approach without information of the objects’ initial positions. An object identification task and an object tracking task are combined under this architecture. The computational time-lag between the two tasks is absorbed by a large amount of frame memory. The tasks are implemented as independent software modules using stereo-vision-based methods which can deal with objects of various shapes with edges, including planar to smooth-curved objects, in cluttered environments. This architecture also leads to failure-recoverable object tracking, because the tracking processes can be automatically recovered, even if the moving objects are lost while tracking. Experimental results obtained with prototype systems demonstrate the effectiveness of the proposed architecture.     

High‐pixel‐rate grating‐light‐valve laser projector

Abstract— A high‐pixel‐rate, high‐contrast (30,000:1) wide‐color‐gamut grating‐light‐valve laser projector is reported. A new optical engine enabling high‐frame‐rate (240 Hz) scan projection is employed. Panoramic wide‐angle‐scan projection with a 64:9 aspect ratio was also developed. Speckle noise is eliminated using a simple but highly efficient technique. The optical throughput efficiency of the grating‐light‐valve laser projector is reviewed.