• 제목/요약/키워드: Maxwell

검색결과 831건 처리시간 0.023초

Electrostatic Spray Deposition Technique for Thin Film Fabrication

  • 최경현
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.2.1-2.1
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    • 2011
  • Electrospray deposition (ESD) technique is fast finding its applicability in the field of thin film device manufacturing processes and the ease and cost efficiency attached to ESD process with possible integration with batch manufacturing technologies is the potential future of thin film device manufacturing. As the name suggests, the deposition phenomenon should solely be a spray achieved through electrostatic forces. In fact it is an imbalance between the surface forces arising because of the surface tension of the liquid to be sprayed and Maxwell stresses which are induced because of the electric field, that pull the liquid downwards from the capillary into a stable jet which further disintegrates into smaller droplets because of coulomb forces and hence a cloud of charged, mono-dispersed and extremely diminutive (sometimes up to femtolitres) droplets is achieved. The present talk is going to be exclusively about the electrospray process concepts, generation and possible applications.

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유리 압축 실험에서의 복굴절 분포 예측 (Prediction of birefringence distribution in cylindrical glass compression test)

  • 이주현;나진욱;임성한;오수익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.95-100
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    • 2004
  • An analysis using FEM simulation was conducted to predict residual stresses and birefringence in simple compressed cylindrical glass as a preliminary part of the optimum design determination of optical lenses. The FEM simulation with the Maxwell viscoelastic constitutive model was used to predict thermal induced residual stresses and birefringence during the compression test considering stress relaxation. Also the linear photoelastic theory was introduced to calculate birefringence from the residual stress state. The simulation results were in good agreement with deformation and birefringence distribution in the existing experimental result.

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동전기 휠을 이용한 전도성 환봉의 나선형 운동과 제어 (Screw Motion and Control of Conductive Rod by Rotating a Spiral Electrodynamic Wheel)

  • 정광석
    • 제어로봇시스템학회논문지
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    • 제17권9호
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    • pp.882-887
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    • 2011
  • A spiral electrodynamic wheel is proposed as an actuator for the contactless conveyance of a conductive rod. When rotating the wheel around the rod, a radial force, a tangential force, and an axial force are generated on the rod and cause a screw motion of the rod. The rotation of the rod is the inevitable result due to traction torque of the wheel and the unintended motion to be excluded. However, the rotating speed of the rod should be measured without mechanical contact to be cancelled out through the controller, so the electrodynamic wheel is used as a sensor measuring the rotating speed of the rod indirectly as well as an actuator. In this paper, we model the magnetic forces by the proposed wheel theoretically and compare the derived model with simulation result by Maxwell, and analyze influences on the magnetic forces by key parameters constituting the wheel. The feasibility of the conveyance system is verified experimentally.

굴곡 및 굴절형 터널 내의 전파 전파의 전송 효율에 관한 연구 (A study on the transmission efficiency of electromagnetic wave propagation in tunnels with bend and fold)

  • 김기래;한경구
    • 전자공학회논문지A
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    • 제33A권12호
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    • pp.25-32
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    • 1996
  • This paper is concenred with a finite volume time domain (FVTD) method for the analyses of transmission efficiency of electromagnetic wave propagation in tunnels with bend and fold. This method is gased on the volume integratio sof the maxwell's equation with respected to arbitrary shaped small polyhedron cells. The advantages of the present mehtod are that the algorithm is very simple since the coordinate system is restricted only to the cartesian, and so the arbitrary shaped boundaries can easily be dealt with since the fields at every center point of the cells are assigned in an average fashion.

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Robust Design of Air Compressor-Driving Quadratic Linear Actuator in Fuel Cell BOP System using Taguchi Method

  • Kim, Jae-Hee;Kim, Jun-Hyung;Kim, Jin-Ho
    • Journal of Magnetics
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    • 제17권4호
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    • pp.275-279
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    • 2012
  • The linear actuator has the inherent drawback of air gap variation because its linear motion is usually guided by the springs, which destabilizes the dynamic performance. In order to design the linear actuator to be insensitive to air gap, this paper describes the robust design of the air compressor driving linear actuator using Taguchi method. The orthogonal arrays are constructed with selected control factors and noise factor for minimum experiment. The control factors are thickness of inner magnet, height of upper yoke, thickness of outer magnet and thickness of lower yoke while noise factor is airgap. The finite element analysis using commercial electromagnetic analysis program "MAXWELL" are performed instead of experiment. ANOVA are performed to investigate the effects of design factors. In result, the optimal robust linear actuator which is insensitive to air gap variation is designed.

Effect of Magnetic Field on the Dielectric Properties $BaTiO_3-MgFe_2O_4$ Composite

  • Tadi, Ravindar;Kim, Yong-Il;Kim, Cheol-Gi;Ryu, Kwon-Sang
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2011년도 임시총회 및 하계학술연구발표회
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    • pp.93-95
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    • 2011
  • In this study we tried to measure the effect of magnetic field on the dielectric properties of $BaTiO_3-MgFe_2O_4$ soft magnetic composite. Composites with different weight percents of ferroelectric and ferromagnetic phases were subjected to magnetic field in the order of 0 to 450 Oe and the variation of the dielectric properties was observed. The Variation of dielectric polarization was discussed in terms of Maxwell-Wagner type polarization in particulate composites.

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Design of Coaxial Magnetic Gear for Improvement of Torque Characteristics

  • Shin, H.M.;Chang, J.H.
    • Journal of Magnetics
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    • 제19권4호
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    • pp.393-398
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    • 2014
  • This paper proposes new types of models that have coaxial magnetic gear (CMG) configurations to increase torque transmission capability. They have flux concentrating structures at the outer low speed rotor, and permanent magnets (PMs) are embedded in the space between stationary pole pieces. The torque performances of the proposed models are compared with those of a basic CMG model. The harmonic torque components due to air gap field harmonics are also analyzed to investigate the torque contribution of each harmonic by using finite element analysis (FEA) and the Maxwell stress tensor. The proposed CMG model is optimized to have high torque density with low torque ripples by response surface methodology (RSM). Compared to the basic CMG model, the proposed model has a huge increase in transmitted torque density, and is very advantageous in term of PM use.

Current Status of the Korean ALMA Project

  • Kim, Jongsoo
    • 천문학회보
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    • 제39권2호
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    • pp.116.1-116.1
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    • 2014
  • Korea officially joined the ALMA (Atacama Large Millimeter/submillimeter Array) project on August 17, 2014. Korea was allowed to apply for the Cycle 2 call-for-proposal before joining the project. Korea submitted 17 proposals, and 4 of them were selected as high-priority. The fund of an 11-year Korean ALMA project in the KASI (Korea Astronomy and Space Science Institute) was approved. The project team formulated an ARC (ALMA Regional Center) node at the KASI and already started its supporting activities for the Korean Astronomical Society. The team also set up a future development plan for ASTE (Atacama Submillimeter Telescope Experiment) and ALMA. A couple of engineers are now doing concept design of a multi-beam receiver system for the ASTE, Because of the ALMA participation, Korea could also access open-use time of ASTE and Mopra telescopes organized by Japan. As of this writing, EACOA (East Asia Core Observatories Association) is now under discussion on making an organization called "East Asian Observatory" and the possible operation of JCMT (James Clerk Maxwell Telescope). I will briefly mention the future prospect of these activities.

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BISTRO: B-fields In STar-forming Region Observations

  • 권우진
    • 천문학회보
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    • 제41권2호
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    • pp.47.2-47.2
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    • 2016
  • We introduce a magnetic field survey of the Gould Belt clouds using the James Clerk Maxwell Telescope (JCMT) POL-2: B-fields In STar-forming Region Observations (BISTRO). POL-2 with SCUBA-2 on JCMT is a unique facility, as it is the only facility world-wide that can map the magnetic field within cold dense cores and filaments on scales of ~1000 AU in nearby star-forming regions, such as Taurus and Ophiuchus. It can provide a link between the B-field measured on arc-minute scales by Planck and BLASTPOL and measurements made on arc-second scales by interferometers such as CARMA, SMA, and ALMA. BISTRO was awarded 224 hours toward 16 fields for the next 3 years and started to take data in the 2016A semester.

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Optical Simulation of Multicolor Cholesteric Liquid Crystal Displays Using Finite-Difference Time- Domain (FDTD) Method

  • Ding, J.M.;Ting, C.L.;Lin, Y.R.;Chen, R.D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1142-1145
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    • 2006
  • The Finite-difference time-domain (FDTD) method is used to directly solve Maxwell's equations, and the techniques required for optical simulation of Bragg reflections of cholesteric liquid crystal (ChLC) displays are introduced in this paper. The simulated results show that the color gamut of a ChLC display can be broadened by using of a circular polarizer on top surface of the ChLC film, and are examined by experiments.

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