• Title/Summary/Keyword: Integrated magnetics

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The Effects of Repetitive Transcranial Magnetic Stimulation Integrated Mirror Therapy on the Gait of Chronic Stroke Patients

  • Cha, Hyun-Gyu;Kim, Myoung-Kwon
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.133-137
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    • 2015
  • This study was conducted to determine the effects of repetitive transcranial magnetic stimulation (rTMS) integrated mirror therapy on the gait of post-stroke patients. Thirty patients who were six months post-stroke were assigned to either the experimental group (n = 15) or the control group (n = 15). Stroke patients in the experimental group underwent rTMS and mirror therapy for the lower limbs, while those in the control group underwent rTMS and sham therapy. Participants in both groups received therapy five days per week for four weeks. A significant difference in post-training gains for the single support phase, step length, stride length and velocity was observed between the experimental group and the control group (p < 0.05). The experimental group showed a significant increment in the single support phase, step length, stride length, swing phase, velocity, cadence, double support phase and step width as compared to pre-intervention (p < 0.05). The control group showed a significant increment in step length, velocity, cadence and step width compared to preintervention (p < 0.05). Further investigation of the availability and feasibility of rTMS integrated mirror therapy for post-stroke patients as a therapeutic approach for gait rehabilitation is warranted.

Core Loss Effects on Electrical Steel Sheet of Wound Rotor Synchronous Motor for Integrated Starter Generator

  • Lee, Choong-Sung;Kim, Ji-Hyun;Hong, Jung-Pyo
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.148-154
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    • 2015
  • 48-V ISG (Integrated Starter Generator) system has attracted attention to improve the fuel efficiency of ICE (Internal Combustion Engine) vehicle. One of the key components that significantly affects the cost and performance of the 48-V ISG system is the motor. In an ISG motor, the core and copper loss make the motor efficiency change because the motor has a broad driving operated range and more diverse driving modes compared with other motors. When designing an ISG motor, the selection of an electrical steel sheet is important, because the electrical steel sheet directly influences the efficiency of the motor. In this paper, the efficiency of the ISG motor, considering core loss and copper loss, is analyzed by testing different types of electrical steel sheets with respect to the driving speed range and mode. Using the results of a finite element method (FEM) analysis, a method to select the electrical steel sheet is proposed. This method considers the cost of the steel sheet and the efficiency according to driving mode frequency during the design process of the motor. A wound rotor synchronous machine (WRSM) was applied to the ISG motor in this study.

High Switching Frequency and High Power Density Three-Level LLC Resonant Converter using Integrated Magnetics (Integrated Magnetics를 적용한 고속 스위칭 및 고전력밀도 3 레벨 LLC 공진형 컨버터)

  • Nam, Kyung-Hoon;Park, Chul-Wan;Bae, Ji-Hun;Ji, Sang-Keun;Ryu, Dong-Kyun;Choi, Heung-Gyoon;Han, Sang-Kyoo
    • Proceedings of the KIPE Conference
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    • 2017.07a
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    • pp.429-430
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    • 2017
  • 본 논문은 Integrated Magnetics(IM)을 적용한 3-레벨 LLC 공진형 컨버터를 제안한다. 제안된 3-레벨 LLC 공진형 컨버터는 스위치 내압이 입력전압의 절반으로 보장되므로 스위칭 손실을 대폭 저감할 수 있어 고주파수 구동에 유리하다. 이에 따라 제안 회로는 리액티브 소자 저감에 유리하나, 회로 동작 상 2개의 공진 인덕터와 1개의 트랜스포머가 요구되는 단점이 있다. 이를 위해 본 논문에서는 자화 인덕터로 공진 인덕터를 대체하는 동시에 모든 자기 소자를 하나로 통합할 수 있는 새로운 IM을 제안하고 그 타당성 검증을 위해 인덕턴스 모델을 통한 이론적 분석과 350W-800kHz급 시작품 제작을 통한 실험결과를 제시한다.

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Fully Integrated Electromagnetic Noise Suppressors Incorporated with a Magnetic Thin Film on an Oxidized Si Substrate

  • Sohn, Jae-Cheon;Han, S.H.;Yamaguchi, Masahiro;Lim, S.H.
    • Journal of Magnetics
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    • v.12 no.1
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    • pp.21-26
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    • 2007
  • Si-based electromagnetic noise suppressors on coplanar waveguide transmission lines incorporated with a $SiO_2$ dielectric layer and a nanogranular Co-Fe-Al-O magnetic thin film are reported. Unlike glass-based devices, large signal attenuation is observed even in the bare structure without coating the magnetic thin film. Much larger signal attenuation is achieved in fully integrated devices. The transmission scattering parameter ($S_{21}$) is as small as -90 dB at 20 GHz at the following device dimensions; the thicknesses of the $SiO_2$ and Co-Fe-Al-O thin films are 0.1 $\mu$m and 1 $\mu$m, respectively, the length of the transmission line is 15 mm, and the width of the magnetic thin film is 2000 $\mu$m. In all cases, the reflection scattering parameter ($S_{11}$) is below -10 dB over the whole frequency band. Additional distributed capacitance formed by the Cu transmission line/$SiO_2$/Si substrate is responsible for these characteristics. It is considered that the present noise suppressors based on the Si substrate are a first important step to the realization of MMIC noise suppressors.

FEM analysis of the magnetic closed type RF integrated inductor

  • Seok Bae;Masahiro Yamaguchi;Arai, Ken-ichi
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.218-219
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    • 2002
  • Recently, RF lumped-element devices are demanded strongly in application of hand-held mobile communication equipments. Many workers have been reported RF integrated inductor as well as air cores. In order to achieve the high Q value, they removed backside of substrate by micro machining process [1] and also another MEMS-like approach such as levitated structure [2]. These approaches are capable of suppressing the parasitic effects, but low reproducibility and high cost problems remain. (omitted)

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LLC Resonant Converter Using A Novel Planar Transformer (새로운 형상의 평면변압기를 이용한 LLC 공진컨버터)

  • Lee, Seung-Min;Noh, Young-Jae;Kang, Cheol-Ha;Jang, Sang-Ho;Kim, Eun-Soo;Chung, Bong-Gun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.6
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    • pp.627-637
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    • 2011
  • To cope with the high power density and low cost in switching power supply, this paper presents a novel planar transformer, which can regulate the leakage inductance of planar transformer used for LLC resonant converter. Modeling and analysis of a novel planar transformer are discussed in detail and a prototype 200W LLC resonant converter is tested to verify.