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101.
Takeshita K. Takeshita S. Hashimoto H. 《Electromagnetic Compatibility, IEEE Transactions on》1979,(1):33-40
The paper analyzes the scattering characteristics of VHF/UHF television broadcasting waves which are obliquely incident on finite length multibundle conductors of overhead power transmission lines. Numerical calculations were made for four-bundle conductors currently employed in Japan; the attenuation, directivity, and frequency characteristics were clarified. To verify the theoretical results, 1:40 scale (for VHF) and 1:10 scale for (UHF) model experiments have been carried out. Agreement between the theoretical results and the measurements was reasonably good. 相似文献
102.
Polymer film-type channel electron multipliers (CEMs) were developed and their characteristics investigated in comparison with bulk-type flexible CEM. As film-type CEMs, a paint-coating-type CEM and a solvent-etching-type CEM were fabricated. The paint-coating-type CEM is made by coating a “paint” which is prepared by dissolving in a solvent an electronically conductive polymeric composition having a high secondary electron emission yield. Up to the present study the mean gain of the film-type CEM, in spite of the lower resistivity of the dynode, seems to be slightly more dependent on the count rate than that of the bulk-type CEM made of the same material. However, the convenience of fabricating the dynode film by coating the dynode-forming paint on the internal surface of any shaped tube or a flexible polymer tube would overcome the slight disadvantage mentioned above. 相似文献
103.
104.
Akahane K Hashimoto M Hada M Takano Y Ono K Kai M Kusama T 《Radiation protection dosimetry》2003,103(1):41-45
As the survival rate of newborns has increased, the number of X ray computed tomography (CT) examinations performed on neonates has been increasing. The exposure doses from CT examinations are known to be higher than those from conventional radiography. Although radiation sensitivity of neonates is higher than that of adults, there are few reports on dose estimates of neonates in CT examinations. Four cylindrical phantoms and one neonatal phantom have been developed to estimate doses to neonates during CT examinations. Using these phantoms and glass dosemeters, absorbed doses were measured. Estimated exposure doses to neonates were higher than those to adults, and our results suggest a need to optimise carefully CT examinations in newborns. 相似文献
105.
Songlan?Yang Zheng-Ming?SunEmail author Hitoshi?Hashimoto 《Materials Research Innovations》2003,7(4):225-230
Ti/Si/TiC powder mixture with molar ratios of 2:2:3 were sintered at various temperatures from 700–1300 °C for 15 min by PDS technique. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for the evaluation of phase composition in different samples for the understanding of the sintering mechanism for this system. Results showed that Ti5Si3 formed as the intermediate phase during sintering. The reaction between Ti5Si3 and TiC as well as Si induces the formation of Ti3SiC2, and TiSi2 appears as the byproduct in this process. At temperature above 1000 °C, TiSi2 reacts with TiC to form Ti3SiC2. High Ti3SiC2 phase content bulk material can be synthesized at 1300 °C for 15 min. 相似文献
106.
Hashimoto KY Yamaguchi M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2001,48(5):1181-1188
This paper reviews the basic properties of shear-horizontal (SH)-type surface acoustic waves (SAWs) and bulk acoustic waves (BAWs). As one of the simplest cases, the structure supporting Bleustein-Gulyaev-Shimizu waves is considered, and their excitation and propagation are discussed from various view points. First, the formalism based on the complex integral theory is presented, where the surface is assumed to be covered with an infinitesimally thin metallic film, and it is shown how the excitation and propagation of SH-type waves are affected by the surface perturbation. Then, the analysis is extended to a periodic grating structure, and the behavior of SH-type SAWs under the grating structure is discussed. Finally, the origin of the leaky nature is explained 相似文献
107.
N. Hashimoto A. Handa M. Nakagawa K. Obara H. Yano O. Ishikawa T. Hata 《Journal of Low Temperature Physics》2007,148(3-4):299-303
We have investigated the turbulence transition of the superfluid 4He flow generated by a vibrating wire. For a 1.2-kHz vibrating wire, we observed intermittent switchings between laminar and
turbulent flows. The switching rate decreases with increasing temperature above 100 mK, until no occurrence of the switchings
at 350 mK. For a 2.4-kHz vibrating wire, we find that the switching rate is much lower than that of the 1.2-kHz vibrating
wire even at low temperatures. This result indicates that a mechanism causing the switchings is influenced by the temperature
and the oscillation frequency of the superfluid flow. 相似文献
108.
Thermal Degradation Under Pulse Operation in Low-Temperature p-Channel Poly-Si Thin-Film Transistors
Shinichiro Hashimoto Koji Kitajima Yukiharu Uraoka Takashi Fuyuki Yukihiro Morita 《Electron Devices, IEEE Transactions on》2007,54(2):297-300
We analyzed the heat generation of a low-temperature polycrystalline thin-film transistor in pulse operation and proposed a technique for accurately measuring its thermal temperature in high-frequency operation. From this measurement, we were able to calculate the time constants for heating and radiation for the first time. At a low frequency, the temperature difference between when the pulse was on and off was remarkable. As the frequency was increased, the maximum and minimum temperatures approached each other and became equal at a frequency of approximately 1 kHz. We also measured the degradation in pulse operation and discussed the relationship between the thermal temperature and the degradation in the pulse operation 相似文献
109.
Pter Baranyi Zoltn Petres Pter Korondi Yeung Yam Hideki Hashimoto 《Asian journal of control》2007,9(2):195-200
The Tensor Product (TP) model transformation method was proposed recently as an automated gateway between a class of non‐linear models and linear matrix inequality based control design. The core of the TP model transformation is the higher order singular value decomposition of a large sized tensor, which requires high computational power that is usually outside of a regular computer capacity in cases of higher dimensionality. This disadvantage restricts the utilization of the TP model transformation to models having smaller dimensionality. The aim of this paper is to propose a computationally relaxed version of the TP model transformation. The paper also presents a 6 dimensional example to show the effectiveness of the modified transformation. 相似文献
110.
Takuya Otani Kenji Hashimoto Takaya Isomichi Akira Natsuhara Masanori Sakaguchi Yasuo Kawakami 《Advanced Robotics》2013,27(22):1197-1206
In previous studies, various stabilizing control methods for humanoids during the stance phase while hopping and running were proposed. Although these methods contribute to stability while hopping and running, it is possibility that the control during the flight phase could also affect the stability. In this study, we investigated whether the control during the flight phase can affect the stability of a humanoid while running. To achieve stable hopping, we developed a control system that accounts for the angular momentum of the whole body during the flight phase. In this system, the angular momentum generated by the motion of the lower body in each time interval is calculated during the flight phase, and the trunk joints are controlled to generate the angular momentum necessary to compensate for the deviation of the waist posture, which is used as the reference point for the motion coordinate system of the robot. Once the proposed control system was developed and simulated, we found that the hopping duration in the unconstrained state was extended. 相似文献