• 제목/요약/키워드: Science and engineering graduate

검색결과 5,126건 처리시간 0.041초

Integration of Current-mode VSFD with Multi-valued Weighting Function

  • Go, H.M.;Takayama, J.;Ohyama, S.;Kobayashi, A.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.921-926
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    • 2003
  • This paper describes a new type of the spatial filter detector (SFD) with variable and multi-valued weighting function. This SFD called variable spatial filter detector with multi-valued weighting function (VSFDwMWF) uses current-mode circuits for noise resistance and high-resolution weighting values. Total weighting values consist of 7bit, 6-signal bit and 1-sign bit. We fabricate VSFDwMWF chip using Rohm 0.35${\mu}$m CMOS process. VSFDwMWF chip includes two-dimensional 10${\times}$13 photodiode array and current-mode weighting control circuit. Simulation shows the weighting values are varied and multi-valued by external switching operation. The layout of VSFDwMWF chip is shown.

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In-situ Observation of Hydride Stability of Vanadium Alloys in Electron Microscope

  • Ohnuki, S.;Takase, K.;Yashiki, K.;Hamada, K.;Suda, T.;Watanabe, S.
    • Applied Microscopy
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    • 제36권spc1호
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    • pp.57-61
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    • 2006
  • High-resolution microscopy was applied for surveying hydride stability in Vanadium alloys, which are candidate for hydrogen storage materials of advanced hydrogen energy systems. $V_2H$ hydride in V alloys was stable at room temperature under the vacuum condition, but it was decomposed during heating up to $100^{\circ}C$. It was confirmed from HRTEM image and FFT that $V_2H$ has a BCT structure, where hydrogen atoms locate at octahedral sites. Crystal orientation was <110> beta// <110> mat., and lattice strain is about 10%. After the decomposition of the hydride, relatively large lattice expansion was observed in the matrix, which suggests that hydrogen atoms should be trapped by lattice defects and included in the matrix. Intensive electron beam also enhanced the decomposition.

Alteration of Physical Properties of Nanoparticle Embedded liquid Crystal Causing the Enhancement of the Performance of LCDs

  • Kobayashi, Shunsuke;Kineri, Tohru;Takatoh, Kohki;Akimoto, Mitsuhiro;Hoshi, Hajime;Nishida, Naoto;Toshima, Naoki;Sano, Satoru
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1473-1476
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    • 2008
  • Doping the nanoparticles of Pd, p-$BaTiO_3$, $SiO_2$ and MgO into LCs alters their physical properties such as $K_{ii}$, $\Delta\varepsilon$, ${\Delta}n$, $\gamma_1$ and $T_{NI}$. Except for $K_{33}$, all these parameters decreases and thus bring the reduction of operating voltage and/or response times.

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Implementation of Video Transfer with TCP-friendly Rate Control Protocol

  • Miyabayashi, Masaki;Wakamiya, Naoki;Murata, Masayuki;Miyahara, Hideo
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.117-120
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    • 2000
  • As the use of real-time multimedia applications increases, a considerable amount of “greedy” UDP traffic would easily dominate network bandwidth and packet loss. As a result, bandwidth available to TCP connections is oppressed and their performance extremely deteriorates. In or-der that both TCP and UDP sessions fairly co-exist in the Internet, it is vital that we consider the fairness among both protocols. In this work, we implement a “TCP-friendly” rate control mechanism suitable to video applications and con-sider its applicability to a real system through observation of the video quality at the receiver and the connection state. It is shown that we can achieve high-quality and stable video transfer fairly sharing the network bandwidth with TCP by applying our rate control at a control interval of 32 times as long as RTT.

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Analysis of Knit Fabric Structure with its Voxel Data

  • Shinohara, T.;Takayama, J.;Ohyama, S.;Kobayashi, A.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.53-56
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    • 2003
  • For identifying how a sample knit fabric is woven a method to obtain positional information of each yarn of the sample from voxel data made out of its x-ray CT images is newly proposed in this paper. The positional information is obtained by tracing the each yarn. The each yarn is traced by estimating a direction of the yarn in a certain small region in which the yarn can be regarded as straight and moving the region slightly along the estimated direction alternately. The yarn direction is estimated by correlating the voxel data in the region with a three-dimensional yarn model. The effectiveness of this method is confirmed by applying the method to voxel data made out of CT images of a knit fabric experimentally.

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Levitation Control Experiment at Standstill in PM LSM Controlled-Repulsive Maglev Vehicle

  • Yoshida, Kinjiro;Takami, Hiroshi;Jozaki, Chiyuki;Kinoshita, Shiauo
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.119-124
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    • 1998
  • This paper proposes a new repulsive-Maglev vehicle in which a vertical type PM linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. A compact control method is developed which is based on the concept of controlling individually the levitation system by armature-current and the propulsion system by mechanical load-angle. The levitation-motion control experiments have carried out successfully together with positioning at standstill. The pitching motion has been compensated for very well by using the zero-phase-current control method proposed here.

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Composition Dependence of Perpendicular Magnetic Anisotropy in Ta/CoxFe80-xB20/MgO/Ta (x=0, 10, 60) Multilayers

  • Lam, D.D.;Bonell, F.;Miwa, S.;Shiota, Y.;Yakushiji, K.;Kubota, H.;Nozaki, T.;Fukushima, A.;Yuasa, S.;Suzuki, Y.
    • Journal of Magnetics
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    • 제18권1호
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    • pp.5-8
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    • 2013
  • The perpendicular magnetic anisotropy of sputtered CoFeB thin films covered by MgO was investigated by vibrating sample magnetometry. Three different $Co_xFe_{80-x}B_{20}$ alloys were studied. Under out-of plane magnetic field, the saturation field was found to increase with increasing the Co content. The magnetization and interface anisotropy energy were obtained for all samples. Both showed a marked dependence on the MgO overlayer thickness. In addition, their variations were found to be non-monotonous as a function of the Co concentration.

Photocatalytic Performance of Barium-doped Strontium Tantalate

  • Kozu, Asuka;Fujimori, Hirotaka;Kim, Ki-Young;Oshiro, Kazunori;Yamamoto, Setsuo;Sakata, Yoshihisa;Imamura, Hayao
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.926-927
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    • 2006
  • [ $Sr_2Ta_2O_7$ ], a layered perovskite compound, has been reported to possess most excellent photocatalytic properties among the layered perovskite materials. Recently, we have demonstrated that $Ba_5Ta_4O_{15}$ that was prepared under a mol ratio of Ba: Ta=1:1 has high photocatalytic performance as well as $Sr_2Ta_2O_7$. In this study, the photocatalyst samples with a mol ratio of Sr: Ba: Ta = (1-x): x: 1 were prepared. The maximum photocatalytic performance was obtained for x= 0.2, which is three times as high as that of undoped $Sr_2Ta_2O_7$.

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