著者
Koji MUROFUSHI Shinji Sakurai Koji Umegaki Kazutoshi Kobayashi
出版者
Japan Society of Physical Education, Health and Sport Sciences
雑誌
International Journal of Sport and Health Science (ISSN:13481509)
巻号頁・発行日
vol.3, pp.116-128, 2005 (Released:2008-01-23)
参考文献数
18
被引用文献数
13 17

The aim of this study was to compare the radius of curvature and the estimated head speed as measured by sensors attached to a hammer with those calculated by video image analysis. The participant was the Japanese record holder(83m47). He threw a hammer with sensors which measured the force exerted along the length of the hammer cable using a tension meter made of a metal plate to which strain gauges were affixed, and the angular velocity perpendicular to the hammer cable using two IC accelerometers whose axes were aligned together with the hammer cable. The radius and speed obtained using the sensors were similar to those obtained from video analysis in values, but were slightly out of phase. This is because measuring the angular velocity by sensors eliminates translational motion and only produces results for rotational motion. The length of time required to obtain these results was shortened by the use of a hammer with sensors. Therefore, the system using sensors attached to a hammer will enable athletes and coaches to interpret the data about each throw while it is still fresh in their minds.
著者
Junichiro Nagao Urmimala Chatterjee Xiangdong Li Jun Furuta Stefaan Decoutere Kazutoshi Kobayashi
出版者
The Institute of Electronics, Information and Communication Engineers
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.18, no.6, pp.20210059, 2021-03-25 (Released:2021-03-25)
参考文献数
32
被引用文献数
1

A three-level gate driver and a power Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) were monolithically integrated to prevent false turn-on, reduce reverse conduction loss and realize fast switching. The proposed gate driver works with an external and an integrated capacitor which supply negative gate voltage. Monolithic integration makes power conversion circuits smaller in size and improves circuit performance due to its lower parasitics. The integrated MIM (Metal-Insulator-Metal) capacitor improves dv/dt immunity. Measurement results showed that the proposed GaN-IC realized fast switching speed of 3.7ns ton and 6.1ns toff, and improved efficiency of an SR buck-converter.
著者
Takuya KOMAWAKI Michitarou YABUUCHI Ryo KISHIDA Jun FURUTA Takashi MATSUMOTO Kazutoshi KOBAYASHI
出版者
The Institute of Electronics, Information and Communication Engineers
雑誌
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)
巻号頁・発行日
vol.E100-A, no.12, pp.2758-2763, 2017-12-01

As device sizes are downscaled to nanometer, Random Telegraph Noise (RTN) becomes dominant. It is indispensable to accurately estimate the effect of RTN. We propose an RTN simulation method for analog circuits. It is based on the charge trapping model. The RTN-induced threshold voltage fluctuation are replicated to attach a variable DC voltage source to the gate of a MOSFET by using Verilog-AMS. In recent deca-nanometer processes, high-k (HK) materials are used in gate dielectrics to decrease the leakage current. We must consider the defect distribution characteristics both in HK and interface layer (IL). This RTN model can be applied to the bimodal model which includes characteristics of the HK and IL dielectrics. We confirm that the drain current of MOSFETs temporally fluctuates in circuit-level simulations. The fluctuations of RTN are different in MOSFETs. RTN affects the frequency characteristics of ring oscillators (ROs). The distribution of RTN-induced frequency fluctuations has a long-tail in a HK process. The RTN model applied to the bimodal can replicate a long-tail distribution. Our proposed method can estimate the temporal impact of RTN including multiple transistors.