• 제목/요약/키워드: Magnetic array

검색결과 285건 처리시간 0.023초

Design and Optimization of 4-Channel SENSE Head Coil

  • 오정민;김용권;류연철;오창현
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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    • pp.16-16
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    • 2003
  • Purpose: Recently, a major interesting method of fast MR imaging is sensitivity encoding (SENSE) using arrays of multiple receiver coils. In this study, we have designed and implemented a 4-channel head array coil and optimized the structure and arrangement of the coil to improve the performance.

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Noninvasive Rx of Breast Cancer by MR-guided High Intensity Focused Ultrasound

  • Moonen, Chrit
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회.한국자기공명학회 2005년도 공동학술대회
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    • pp.77-78
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    • 2005
  • A specific FUS-MRI platform was designed for breast cancer treatment. phased array technologies, sideways FUS transmission, and spatio-temporal temperature control in the complete region of interest, were combined for a novel therapy approach with enhanced safety and afficacy. A phase I clinical trial will start soon.

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MODE CONTROL OF GUIDED WAVE IN MAGNETIC HOLLOW CYLINDER USING ELECTROMAGNETIC ACOUSTIC TRANSDUCER ARRAY

  • FURUSAWA, AKINORI;KOJIMA, FUMIO;MORIKAWA, ATSUSHI
    • Nuclear Engineering and Technology
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    • 제47권2호
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    • pp.196-203
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    • 2015
  • The aim of this work is to demonstrate a method for exciting and receiving torsional and longitudinal mode guided waves with an electromagnetic acoustic transducer (EMAT) ring array. First of all, a three-dimensional guided wave simulator is developed in order to numerically analyze the propagation of the guided wave. The finite difference time domain method is used for the simulator. Second, two guided wave testing systems using an EMAT ring array are provided: one is for torsional mode (T-mode) guided wave and the other is for longitudinal mode (L-mode). The EMATs used in the both systems are the same in design. A method to generate and receive the T- and L-mode guided waves with the same EMAT is proposed. Finally, experimental and numerical results are compared and discussed. The results of experiments and simulation agree well, showing the potential of the EMAT ring array as a mode controllable guided wave transmitter and receiver.

Large Area Plasma for LCD Processing by Individyally Controlled Array Sources

  • Kim, Bong-Joo;Kim, Chin-Woo;Park, Se-Geun;Lee, Jong-Geun;Lee, Seung-Ul;Lee, Il-Hang;O, Beom-Hoan
    • Journal of Information Display
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    • 제3권2호
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    • pp.26-30
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    • 2002
  • Large area plasma source has been built for LCD etcher by an array of $2{\times}2$ ICP sources. Since only one RF power supply and one impedance matching network is used in this configuration, any difference in impedances of unit RF antennas causes unbalanced power delivery to the unit ICP. In order to solve this unavoidable unbalance, unit antenna is designed to have a movable tap, with which the inductance of each unit can be adjusted individually. The plasma density becomes symmetric and etch rate becomes more uniform with the impedance adjustment. The concept of adding axial time-varying magnetic field to the single ICP source is applied to the array ICP source, and is found to be effective in terms of etch rate and uniformity.

평면형 구조와 Halbach 자석배열 선형모터를 이용한 리니어 XY 스테이지의 설계 (Design of Linear XY Stage using Planar Configuration and Linear Motors with Halbach Magnet Array)

  • 김기현;이문구
    • 한국생산제조학회지
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    • 제19권4호
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    • pp.553-561
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    • 2010
  • In flat panel display or semiconductor industries, they install the equipments with fine line width and high throughput for fabrication and inspection. The equipments are required to have the linear stage which can position the work-piece with high speed, fine resolution on wide range of motion. In this paper, a precision planar linear XY stage is proposed. The stage has a symmetric planar window configuration and is guided by air-bearings on granite plate. The symmetric planar window configuration makes the stage has robustness against dynamic and thermal disturbances. The air-bearings let the stage move smooth on straight guide bar and flat granite surface. The stage is actuated by linear motor with Halbach magnet array (HMA). HMA generates more confined magnetic flux than conventional array. The linear motors are optimized by using sequential quadratic programming (SQP) with the several constraints that are thermal dissipation, required power, force ripple and so on. The planar linear XY stage with the symmetric planar configuration and the linear motors is implemented and then the performance such as force ripple, resolution and stroke are evaluated.