Search Results 1-20 of 5881

  • 耐震診断による上部構造評点を用いた木造在来軸組構法住宅の地震特性能評価  [in Japanese]

    岩西 正晴 , 岩井 哲

    … This research aims to investigate the relationship between the amount of bearing-wall in an earthquake diagnosis evaluation, the fundamental natural frequency based on the micro-tremor measurement and the actual earthquake damage to conventional wooden-framed houses in Japan. …

    広島工業大学紀要. 研究編 (42), 191-197, 39479-00-00


  • The switching mechanisms of social network densification

    Kobayashi Teruyoshi , Genois Mathieu

    … Densification and sparsification of social networks are attributed to two fundamental mechanisms: a change in the population in the system, and/or a change in the chances that people in the system are connected. … We apply the method to networks of face-to-face interactions of individuals and reveal that the main mechanism that causes densification and sparsification occasionally switches, the frequency of which depending on the social context. …

    Scientific Reports 11(1), 3160, 2021-02-04


  • Periodic fluctuations of streamwise vortices in inertia-dominated intersecting flows

    N. Burshtein , K. Zografos , A. Q. Shen , R. J. Poole , S. J. Haward

    … The unique steady-state features determine the onset parameters, dynamics, and frequency of time-periodic fluctuations that develop at higher Re. … Additionally, these findings contribute to the fundamental knowledge on vortical motion with the potential to improve the control over vortex-induced vibrations on obstacles in both terrestrial and marine environments. …

    Physics of Fluids 33(1), 014106, 2021-01-11


  • Fundamental Study on Equivalent Circuit Model of Spiral Coil for Low Frequency Band

    OKINAGA Tomoki , YAMAMOTO Takahiko , KOSHIJI Kohji

    <p> In recent years, wireless power transmission technology has attracted a lot of attention. By using wireless power transmission, it is possible to easily supply power to tablets and smartphon …

    Journal of the Japan Society of Applied Electromagnetics and Mechanics 29(1), 105-110, 2021


  • Development of Noise Control System for Ultra-compact Mobility by Plate Vibration:(Fundamental Consideration on Performance of Giant Magnetostrictive Actuator)  [in Japanese]

    Kato T. , Kitamura T. , Maehara F. , Nakayama H. , Ikeda K. , Endo A. , Kato H. , Narita T.

    … In this paper, we created an analysis model of the GMA and considered magnetostrictive force and the frequency characteristics of the proposed GMA by electromagnetic field analysis.</p> …

    Transaction of the Magnetics Society of Japan Special Issues 5(1), 44-49, 2021


  • Reduction of Input Current Harmonics Using Dual Inverter for Motor Drive

    Okumura Ren , Haga Hitoshi

    … In the proposed method, the inverter connected to the DC power supply switches based on the fundamental electric angular frequency of the motor. … Therefore, the carrier-frequency-order component of the input current harmonic can be reduced greatly, which helps reduce the current ripple of the filter capacitor across the DC-bus. …

    IEEJ Journal of Industry Applications 10(3), 348-356, 2021


  • Fundamental Study on Fretting Corrosion in Solid Breeder Blanket

    TAKAHASHI Naoki , KONDO Masatoshi , KIM Jae-Hwan , NAKAMICHI Masaru

    … The purpose of the present study is to investigate the fundamental behaviors of fretting corrosion between Li<sub>2</sub>TiO<sub>3 </sub>pebble and the F82H plate. … The small pebble of Li<sub>2</sub>TiO<sub>3 </sub>or Al<sub>2</sub>O<sub>3 </sub>was placed on the plate specimen of F82H in point contact, and the plate specimen was oscillated horizontally and lineally at the frequency of 50 Hz and the amplitude of 120 µm. …

    Plasma and Fusion Research 16(0), 2405032-2405032, 2021


  • Curiosity Guided Fine-Tuning for Encoder-Decoder-Based Visual Forecasting

    KAMIKAWA Yuta , HASHIMOTO Atsushi , SONOGASHIRA Motoharu , IIYAMA Masaaki

    … <p>An encoder-decoder (Enc-Dec) model is one of the fundamental architectures in many computer vision applications. … (CurioFT), which puts more weight on uncommon input patterns without explicitly knowing their frequency. …

    IEICE Transactions on Information and Systems E104.D(5), 752-761, 2021


  • An ultra-broadband power amplifier by using a simple analysis method

    Zhang Zhiwei , Cheng Zhiqun , Jin Liwei , Liu Guohua

    … The relationship between the operating frequency and load impedance is analyzed for class-EFJ PAs. … In addition, the second harmonic impedance is obtained by combining the selected fundamental impedance and load-pull simulation. … The ACLR is smaller than -27<i>.</i>2 dBc in the same frequency band with an average output power of 35.2 dBm.</p> …

    IEICE Electronics Express 18(8), 20210057-20210057, 2021


  • Correlation Analysis between Density and Magnetic Field Low Frequency Fluctuations in Improved Confinement Mode on LHD

    HU Wenqing , KOBAYASHI Tatsuya , SUZUKI Yasuhiro , YOSHINUMA Mikiro , TOKUZAWA Tokihiko , IDA Katsumi

    … While the fundamental frequency peak shows a high correlation between the density fluctuation and the magnetic fluctuation, the higher harmonic components have smaller or even negligible correlation. …

    Plasma and Fusion Research 16(0), 2402031-2402031, 2021


  • Impact of adjacent-channel interference on transmission performance in asynchronous FBMC/OFDM systems

    Tabata Hiroki , Suganuma Hirofumi , Maehara Fumiaki

    … <p>This paper investigates adjacent-channel interference (ACI) influence on asynchronous systems consisting of filter bank multicarrier (FBMC) and orthogonal frequency-division multiplexing (OFDM), under multipath fading channels. …

    IEICE Communications Express 10(4), 186-192, 2021


  • Effectiveness evaluation of polarization in OAM multiplexing

    Ito Yuki , Saito Shuhei , Suganuma Hirofumi , Ogawa Kayo , Maehara Fumiaki

    … Numerical results, obtained through computer simulations, provide the mode selectivity and system capacity with respect to link distance and carrier frequency.</p> …

    IEICE Communications Express 10(4), 199-205, 2021


  • A Study on Extreme Wideband 6G Radio Access Technologies for Achieving 100 Gbps Data Rate in Higher Frequency Bands

    SUYAMA Satoshi , OKUYAMA Tatsuki , KISHIYAMA Yoshihisa , NAGATA Satoshi , ASAI Takahiro

    … <p>In sixth-generation (6G) mobile communication system, it is expected that extreme high data rate communication with a peak data rate over 100 Gbps should be provided by exploiting higher frequency bands in addition to millimeter-wave bands such as 28 GHz. …

    IEICE Transactions on Communications, 2021



    IWAKI Hideaki , TADA Hiroyuki , NOHMI Hitoshi

    <p> 山岳トンネル工事における肌落ち・落石等による死傷災害の防止対策のために,切羽の変状を面的かつ非接触で捉えることが可能なミリ波高速イメージングレーダーに着目し開発を行っている.</p><p> 本報では,切羽の肌落ち・落石等の前兆を,削孔作業等に伴う切羽表面の微小な動きや振動数の変化と考え,それらが同レーダーで捉える可能性を,パネル試験体を用いた基本試験およ …

    Journal of Japan Society of Civil Engineers, Ser. F3 (Civil Engineering Informatics) 77(2), II_16-II_22, 2021


  • Fundamental Experiment on Invisible Crack Detection of Concrete Covered with Fiber Reinforced Polymer (FRP) through Electrical Impedance Variations and Phase Transition  [in Japanese]

    Tada Kenji , Takeda Yuji , Hasegawa Hiroaki , Yoshitake Isamu

    <p>本研究は,電気的インピーダンスおよび位相角の変化を基に,繊維強化ポリマー(FRP)シートで覆われたコンクリート表面近傍にあるひび割れを検出する技術開発を目的としている。基礎的実験として,表面直下に人工ひび割れを設けたコンクリート立方体をFRPシートで被覆した試験体を用いた。本研究の試験では,1kHzから8MHzまでの交流電圧を試験体に負荷させた状態におけるインピーダンスおよび位相 …

    Concrete Research and Technology 32(0), 49-57, 2021


  • Formant estimation from speech signal using the magnitude spectrum modified with group delay spectrum

    Chowdhury Husne Ara , Rahman Mohammad Shahidur

    … Thus, the magnitude spectrum modified with its GD spectrum, referred to as the modified spectrum, is found to significantly improve the estimation of formant frequency over traditional methods. … The accuracy is tested on synthetic vowels for a wide range of fundamental frequencies up to the high-pitched female speaker range. …

    Acoustical Science and Technology 42(2), 93-102, 2021


  • Power Density and Electric Field Distribution at End-turn Stress Grading System of Inverter-fed Rotating Machine under PWM Waveform  [in Japanese]

    Umemoto Takahiro , Nakamura Takahiro , Karasawa Kazunari

    … It has been revealed that the high frequency repetitive pulses cause the local heating and electric field enhancement at the end-turn stress grading (SG) system, however, few paper deals with the stresses under the pulse width modulation (PWM) waveforms. … In this research, potential distributions, electric field and time-averaged power densities under the PWM waveforms are numerically investigated, as functions of the carrier and the fundamental frequency. …

    IEEJ Transactions on Fundamentals and Materials 141(3), 164-171, 2021


  • Behaviors of Surge Frequencies in Multi-stage Axial Flow Compressors over a Wide Range of Speeds

    Yamaguchi Nobuyuki

    … The fundamental behaviors of deep surge frequencies in axial-flow compressors have come to be described as a rather simple framework for low pressure-ratio compressors, in terms of two essential reduced frequencies concerning resonance frequencies and surge frequencies, on the basis of numerical-experimental results. …

    International Journal of Fluid Machinery and Systems 14(1), 62-79, 2021


  • A Comparison of Mating Calls Recorded around the Type Localities of <i>Rana tagoi</i> and <i>R. neba</i> (Amphibia: Anura: Ranidae)

    SHIMADA Tomohiko , SANDA Maki , ETO Koshiro

    … However, through a comparison of advertisement calls around the type localities of both species, we found that interspecific differences are instead apparent in the fundamental frequencies, not in the dominant frequencies. … are more easily distinguished by their unique first notes, which can be differentiated by the strong frequency modulation, longer and fewer pulses, and lower pulse rate. …

    Current Herpetology 40(1), 54-65, 2021



    WONGTHONGSIRI Supawat , HIROSE Sohichi , WANG Bin

    … The numerical model is formulated based on the boundary element method with elastodynamic traction and displacement fundamental solutions in frequency domain, where the boundary integral equations, including artificial boundaries, are discretized with constant elements. …

    Journal of JSCE 9(1), 51-62, 2021


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