Miniaturization design method and performance evaluation of prototype permanent‐magnet synchronous motor optimally designed by thermomagnetic field coupling analysis

This paper reports on the results of the miniaturization design of a permanent magnet synchronous motor, for which an optimal design technique based on thermomagnetic field coupling analysis is used. We derived the optimal solution for various motor flatness ratios and determined the relationship between the motor size and the flatness ratio. For motors with different flatness ratios, we calculated the speed–torque characteristics by considering the voltage, temperature rise, and demagnetization limits and compared them. Moreover, we manufactured and tested the smallest designed motor. The measured temperature rises demonstrated the high accuracy of the proposed miniaturization design. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(2): 58–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22279     

Basic study of a ship navigator's mental workload using salivary NO\documentclass{article}\usepackage{amsmath}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{amsfonts}\pagestyle{empty}\begin{document}$_{3}^{-}$ \end{document}

Evaluation of the mental workload during training for ship handling has usually depended on professionals (captain, pilot) who have lots of experience on board. We are attempting to evaluate a ship navigator's mental workload based on a physiological index. The physiological indices, namely heart rate variability (R–R interval), nasal temperature, and salivary amylase, are good indices for reading the mental workload during ship handling. Moreover, we find the possibility of using salivary NO$_{3}^{-}$ as a good index for evaluating the ship navigator's mental workload. Salivary NO$_{3}^{-}$ is expected to have a specific characteristic to represent quick response on the spot and the trend. We confirmed the response of students during simulator training, and then carried out the experiment on professionals on a real ship. We propose that salivary NO$_{3}^{-}$ can show a ship navigator's stress for ship handling in the simulator and on a real ship. This work to evaluate the ship navigator's mental workload using salivary NO$_{3}^{-}$ is the first attempt worldwide. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Characterization of morphology and mechanical properties of block copolymers using atomic force microscopy: Effects of processing conditions

The effect of preparation methods and processing conditions on morphology and mechanical properties of poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) triblock copolymer were investigated with atomic force microscopy (AFM) tapping mode and nanomechanical mapping, tensile testing, and gel permeation chromatograph (GPC). It was found that the samples prepared by solution casting and melt processing show large difference in morphology and mechanical properties. High shear rate does not induce alignment of lamellar block copolymer melts but leads to serious degradation of SEBS. As increase of rotational speed from 0 to 400 rpm, the molecular weight including M_n and M_w decreases from 67,100 to 26,000 and 70,000 to 43,000, respectively. Such large molecular weight decrease causes greatly decreased tensil strength but there is almost no evident effect on the well-phase separated morphology and Young's modulus of the SEBS. The Young's modulus distribution revealed by nanomechanical mapping becomes narrow as the increase of rotational speed. The amount of SEBS molecular having higher Young's modulus, which play a very important role in tensile strength of SEBS, also decreases.     

基于计算机视觉的人体内腔三维重建技术综述

医生通过内窥镜观察的人体内腔显示为二维图像,不能立体地展现内腔环境中病灶、血管及邻近组织的关系,而内腔三维重建及可视化技术能够清晰、全面地展现病灶及其他组织的三维形态,更好地辅助医生进行精准的手术判断.将人体内腔环境中的三维重建技术分为主动式测量方法与被动式测量方法,分类综述基于结构光、飞行时间、双目立体视觉、单目视觉...     

Tritium depth profile in matter using an imaging plate

A method to detect tritium non-destructively in regions deeper than the escape depth of beta rays is being developed using bremsstrahlung induced by beta rays with an imaging plate (IP). An IP made of europium-doped BaFBr(I), a photostimulated luminescence (PSL) material, is a two-dimensional radiation sensor. The bremsstrahlung energy spectrum is a continuum with photon energies, varying based on the atomic number and thickness of the target (or absorbing) material. When tritium migrates into matter, the bremsstrahlung energy spectrum distribution would change. The PSL intensity of the IP is affected by this energy spectrum variation. In order to quantify the amount of tritium in deeper regions with the IP technique, a tritium depth profile is required.In this study, a new method of obtaining a tritium depth profileusing the combined technique of the IP and thin absorbers is presented.     

Power reduction using adiabatic charge method for PDP driver circuit

Abstract— By applying an energy‐recovery method to their driver circuits, the circuit power consumption of plasma displays can be reduced. However, further power reduction is necessary for large‐sized higher‐resolution displays such as used for Super HDTV. The ideal adiabatic charge method has been proven to be able to minimize circuit resistive element power consumption to 81 % of the conventional energy‐recovery‐circuit resistive‐element loss. An experimental pseudo‐adiabatic charge circuit that reduces the power consumption to about 90% of a conventional circuit has been demonstrated. The power consumption caused by both the resistance loss and the discharge loss of the switching‐element parasitic capacitances was analyzed.     

Nonlinear control for rotational movement of cart-pendulum system using homoclinic orbit

In this paper, we deal with the control method for rotational movements of a pendulum using a separatrix. We design a controller that attains a homoclinic motion or a heteroclinic motion of the pendulum and the asymptotic stability of the cart by using a kind of forwarding control design. First, we derive a controller that converges to a homoclinic orbit via a Lyapunov function of the pendulum subsystem. Next, we give a nonlinear stabilizing controller via another Lyapunov function of the cart subsystem. Moreover, using the third Lyapunov function and adding a complementary control input, we guarantee that the pendulum converges to the homoclinic orbit and the cart is stabilized. Finally, the simulation and the experiment using the rapid controller prototyping system based on MATLAB/Simulink are performed to demonstrate the forward upward circling and the giant swing of the pendulum.     

基于6-DOF解耦操作臂的空间遥操作控制及运动学分析

针对由6-DOF解耦操作臂及其末端手爪组成的操作臂系统,设计了符合工程实际的遥操作控制策略,并提出了一种简单的运动学解算方法.采用Motoman工业操作臂,对提出的方法进行了实验验证.实验结果证明了所提方法的可行性.     

Performance evaluation of immunity-based statistical en-route filtering in wireless sensor networks

Statistical en-route filtering (SEF) schemes can detect and eliminate false data injection attacks in wireless sensor networks. However, SEF does not address the identification of the compromised nodes which are injecting false reports. Therefore, we have proposed an immunity-based SEF to identify compromised nodes and achieve earlier detection of false reports. In the proposed scheme, each node has a list of neighborhood nodes and assigns credibility to each neighboring node. Each node can update the credibility of a neighboring node based on the success or failure of filtering and communication, and can then use the updated credibility as the probability of the next communication. In this article, some simulation results show that the immunity-based SEF outperforms the original SEF.     

Efficiency analysis of telescopic-legged bipedal robots

This paper investigates the stability of underactuated bipedal walking incorporating telescopic-leg actuation. In human walking, knee joints of swing and support legs are bent and stretched. The telescopic legs mimic the motion of the center of mass of human legs via their telescopic motion during the stance phase. First, underactuated telescopic-legged biped robot models are introduced. Second, an output-following control law is applied to the linearized equation of motion of the robot, and the controlled robot’s equation is then specified as a linear time-varying system. The error transition equation is developed to evaluate the stability during the stance phase. Numerical calculations are performed to show the influences of leg telescopic motion on the stability.