• Title/Summary/Keyword: external field

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Influence of axial magnetic field on the plasma density on the substrate in helical resonator (헬리칼 공명 플라즈마의 기판플라즈마밀도에 미치는 축방향자계의 영향)

  • Kim, Tae-Hyun;Kim, Moon-Young;Jang, Sang-Hun;Tae, Heung-Sik
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.376-378
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    • 1997
  • Plasma density and its axial distribution and uniformity on the substrate in a helical resonator plasma in the external magnetic field have been measured using Langmuir probes. Net RF power is set to 200W and chamber pressure is varied from $1{\times}10^{-1}Torr$ to $1{\times}10^{-4}Torr$. There are three kinds of external magnetic field structure applied on the helical resonator plasma. One is a uniform magnetic field, another is a plus gradient magnetic field and the third is a minus gradient magnetic field. Of the three magnetic field structure, the minus gradient magnetic field is found to show the highest increase in plasma density on the substrate compared with other magnetic structures. In order to avoid radial density ununiformity, weak magnetic fields under 100Gauss are applied.

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Semi-automatic Field Morphing : Polygon-based Vertex Selection and Adaptive Control Line Mapping

  • Kwak, No-Yoon
    • International Journal of Contents
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    • v.3 no.4
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    • pp.15-21
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    • 2007
  • Image morphing deals with the metamorphosis of one image into another. The field morphing depends on the manual work for most of the process, where a user has to designate the control lines. It takes time and requires skills to have fine quality results. It is an object of this paper to propose a method capable of realizing the semi-automation of field morphing using adaptive vertex correspondence based on image segmentation. The adaptive vertex correspondence process efficiently generates a pair of control lines by adaptively selecting reference partial contours based on the number of vertices that are included in the partial contour of the source morphing object and in the partial contour of the destination morphing object, in the pair of the partial contour designated by external control points through user input. The proposed method generates visually fluid morphs and warps with an easy-to-use interface. According to the proposed method, a user can shorten the time to set control lines and even an unskilled user can obtain natural morphing results as he or she designates a small number of external control points.

저전계영역에서 M$_{1}$-P-M$_{2}$형 고분자재료의 전기전도 1

  • 이덕출;임광현
    • 전기의세계
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    • v.29 no.11
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    • pp.727-732
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    • 1980
  • The main purpose of this paper is to study on the effect of contact state between metal-polymer interface in electrical conduction of polymeric materials under low field region. The electric conduction of polythylene (PE) sandwitched in between two gold (Au) electrodes was lower than that of PE Sandwitched in between two Aluminium (Al) electrodes under low external field. The discharge current of PE which have been treated by the high field application is also obtained some results under no external field. The obtained results can suggest that the material of electrode come to influence on the electrical conduction of polymeric materials and are important as a basis for analysing the data on TSC. It is also suggestive that results of observation must be considered in cases of insulation design of electrical machinery.

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Analytic Model of Spin-Torque Oscillators (STO) for Circuit-Level Simulation

  • Ahn, Sora;Lim, Hyein;Shin, Hyungsoon;Lee, Seungjun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.1
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    • pp.28-33
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    • 2013
  • Spin-torque oscillators (STO) is a new device that can be used as a tunable microwave source in various wireless devices. Spin-transfer torque effect in magnetic multilayered nanostructure can induce precession of magnetization when bias current and external magnetic field are properly applied, and a microwave signal is generated from that precession. We proposed a semi-empirical circuit-level model of an STO in previous work. In this paper, we present a refined STO model which gives more accuracy by considering physical phenomena in the calculation of effective field. Characteristics of the STO are expressed as functions of external magnetic field and bias current in Verilog-A HDL such that they can be simulated with circuit-level simulators such as Hspice. The simulation results are in good agreement with the experimental data.

무한 소폭 전기유변 스퀴즈 필름 댐퍼의 해석

  • 정시영
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1994.06b
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    • pp.19-29
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    • 1994
  • Since Winslow (1) has reported an electro - theological (ER) effect which features remarkable and reversible changes in the properties of the fluid due to an imposed external electric field, numerous applications of ER fluids in mechanical devices, such as clutches, control valves, active dampers, and etc. have been proposed to improye dramatical ly their performances (2,3). When the external electric field is imposed to the ER fluid, it behaves as a Bingham fluid, displaying a field dependent yield shear stress which is widely variable. Without the electric field, the ER fluid has a reversible and constant viscosity so that it flows as a Newtonian fluid. Another salient feature of the ER fluid is that the time required for the variation is very short (< 0.001 sec) (4-6). These attractive.characteristics of the ER fluid provide the possibility of the appearance of new engineering technology , for instance, an active vibration control system. Recently, the application of the ER fluid to rotor-bearing systems has been also initiated.

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Assessment of Characteristics and Field Applicability with TPA By-Product as Alternative External Carbon Source (대체 외부탄소원으로서의 TPA 생산부산물 특성 및 현장적용성 평가)

  • Jung, In-Chul;Jun, Sung-Gyu;Sung, Nak-Chang
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.5
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    • pp.480-486
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    • 2006
  • On account of exchanging main process from chemical precipitation for MLE(Modified Ludzark-Ettinger), an external carbon source was required for supplementation of carbon source shortage that was needed biological denitrification in the S sewage treatment plant(S-STP). In this study, NUR(nitrate uptake rate), OUR(oxygen uptake rate) test and a field application test was conducted for the applicability assessment of Terephtalic acid(TPA) by-product contained about 4.7% acetate as alternative external carbon source. As the results, TPA by-product shows more rapid acclimation than methanol, 8.24 mg ${NO_3}^--N/g$ VSS/hr specific denitrification rate, 3.70 g $COD_{Cr}/g\;NO_3$ C/N ratio and 99.4% readily biodegradable COD contents. In the results of field application, the nutrient removal efficiency was high and effluent T-N concentration is 8.2 mg/L. It is concluded that TPA by-product is the proper alternative external carbon source.

Forced Resonant Type Cutoff Cavity-Backed Aperture Antennas Loaded with a Single External Reactance

  • Kim Ki-Chai;Hirasawa Kazuhiro
    • Journal of electromagnetic engineering and science
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    • v.5 no.3
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    • pp.105-111
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    • 2005
  • This paper presents the basic characteristics of a cutoff cavity-backed aperture antenna with a feed post and a parasitic post inserted parallel to the aperture. It is shown that this type of antenna forcibly resonates the cutoff cavity by adding a single external reactance to the parasitic post. The Galerkin's method of moments is used to analyze integral equations for the unknown electric current on each post and the aperture electric field on the aperture. The value of an external reactance for forced resonance is analytically obtained by deriving a determining equation. Also the current distribution on each post, aperture electric field distributions, and the radiation patterns are discussed. The theoretical analysis is verified by the measured return loss and radiation patterns.

Performance Analysis of External Rotor Type Permanent Magnet Motor/Generator (외전형 영구자석형 전동/발전기의 성능해석)

  • Jang, S.M.;Go, J.W.;Yoon, I.K.;Lee, S.H.;Jeong, S.S.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.641-643
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    • 2002
  • Synchronous generator needs slip-ring and brush for supplying current to rotor with external source. but slip-ring and brush have some problems to supply DC power to field winding with friction and high power loss due to brush voltage drop at high field current. Thus synchronous generator have been designed to brushless machine. Brushless synchronous machines of using permanent halbach array can composed without back core and coreloss. In this paper, analyse on the characteristics of external rotor type permenant magnet brushless with halbach array.

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Determination of the voltage distribution in the external electrode fluorescent lamps for the backlight unit of large-size LCD

  • Choi, Jae-Young;Kim, Young-Youb;Ko, Jae-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1374-1377
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    • 2006
  • The voltage distribution of an external electrode fluorescent lamp(EEFL) having a gas pressure of 50 torr and a gas composition of Ne:Ar with a ratio of 90:10 has been estimated by varying the distance between the two external electrodes and monitoring the change of the lamp voltage. The estimated voltage gradient, which represents the electric field in the positive column of the EEFL, was very sensitive to the electrode area of EEFL and was in the range of $13\;{\sim}\;27\;V/cm$ at the electrode length of $15\;{\sim}\;31\;mm$. Changing the lamp current in the range $3\;{\sim}\;5\;mA$ did not make noticeable difference in the electric field of the positive column. Theses results may serve as basic data for the optimization of electric and optic characteristics of EEFL.

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