• Title/Summary/Keyword: Field effect

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The Characteristics of Piezoelectric Strian Constants on PNN-PZ-PT Ceramics (PNN-PZ-PT계 세라믹스의 압전변위특성)

  • 정수태;남효덕;조상희
    • Journal of the Korean Ceramic Society
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    • v.26 no.6
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    • pp.802-810
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    • 1989
  • The temperature dependence of piezoelectric strain constant and the electric field induced strain are investigated as a function of PT in 0.5[xPT-(1-x)PZ]-0.5PNN ceramics. The piezoelectric strain constant d31 has the highest value(360$\times$10-12m/V) at PT=0.68. The temperature dependence of d31 is improved as Curie temperature of sample is increased, and the electric field dependence of induced strain is decreased with the coercive field increased. This ceramic system shows both piezoelectric effect and electrostrictive effect under the applied electric field. The piezoelectric of tetragonal phase is higher than that of rhombohedral phase, and the magnitude of electrostrictive constant is appeared in the order of morphotropic, rhombohedral and tetragonal phase. The piezoelectric strain constant with applied field must be considered theelectrostrictive effect due to 90$^{\circ}$domain wall displacements, and the displacement of bimorph type actuator agrees with the calulated value well.

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배경조건에 따른 Visual Field에서의 Stationary Field의 변화

  • 기도형;정의승;신용탁
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1994.04a
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    • pp.375-384
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    • 1994
  • Depending upon the eye and head movement, the visual field is often classified into three categories; stationary field, eye field and head field. To investigate the effect of background condition on the size of stationary field, an experiment was conducted, in which the subject was instructed to search a target with distinct orientations. In each trial, a single target was presented on the rear-view screen projected by the two-field tachistoscope, with the visual angle subtended 4.3.deg. vertically and horizontally. Density, meridian and subject showed a significant effect on stationary field at .alpha.=0.01, where density was inversely proportional to the size of stationary field. The size of the stationary field on horizontal axis was larger than that on vertical axis, and that on right and below meridian also larger than on left and lower meridian. The shape was found to be horizontally oriented oval and statistically asymmetric with respect to horizontal and vertical axes. The regression equation to predict stationary field on the given background condition was suggested. These results were expected to be used as a designing guideline when arranging displays and controls on panels such as automobile display panels, cockpits, etc. In addition, it can be inferred from the results that eye field and head field are also subjected to the influence of background condition.

An Effect of Magnetic Field on VDT Work (VDT 작업시 자기장이 인체에 미치는 영향에 관한 연구)

  • 박재희;김철중;이남식;김진호
    • Proceedings of the ESK Conference
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    • 1992.10a
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    • pp.77-83
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    • 1992
  • The effect of magnetic field on VDT work has not been clarified yet, but many studies repoerted that magnetic field could cause of the cancers. Many developed countries have set the criteria of magnetic field and produce the VDT which has lower magnetic value. The purpose of this study was to measure the intensity of magnectic field from VDT. For this purpose three experiments were performed. The first was designed to measure the intensity of magnetic field by distances(30,60,90 cm) and directions. The second was to compare the intensities between VDT and Color TV. The last was to evaluate the eye protec- tion glasses. The reults showed that the intensity of magnetic field was lowered in proportion to the distance $r^{3}$and both lateral sides of the VDT marked high values compared to the frontal and back sides. On the same distance (30 cm) color TV marked high value to the VDT. But on the normal work distance (TV: 100 cm, VDT: 30 cm) there was little difference, Eye protection glasses could not protect the magnetic field physically.

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Effect of Magnetic Field on NOx Removal for Wire-Plate Plasma Reactor (선대 평판형 플라즈마 반응기에서 NOx 제거에 미치는 자계의 영향)

  • Park, J.Y.;Son, S.D.;Han, S.B.;Lee, D.H.;Kim, J.D.;Mun, Y.H.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2251-2252
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    • 1999
  • In this paper, the effect of magnetic field was measured on NOx removal characteristics for wire-plate plasma reactor with magnetic field applied to electric field vertically. NOx from simulated diesel engine flue gas are decomposed by the corona discharge of DC, AC and Pulsed voltages in wire-plate reactor. Consumption power increased with increasing discharge voltage. When magnetic field was applied to electric field vertically, consumption power decreased. NOx removal rate and arc transition voltage of plasma reactor with magnetic field were higher than those of plasma reactor without magnetic field.

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The Effect of Mechanical Stress and Electric Field on the Morphotropic Tetragonal and Rhombohedr Phase Boundary in PZT System : Thermodynamic Consideration (PZT계의 정방정상과 능면체정상의 경계조성에 대한 기계적 응력과 전기장의 영향 : 열역학적 고찰)

  • 천채일;김호기
    • Journal of the Korean Ceramic Society
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    • v.30 no.10
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    • pp.859-865
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    • 1993
  • Morphotropic tetragonal and rhombohederal phase boundary(MPB) in PZT system was calculated and the effect of mechanical stress and electric field on the MPB was examined using phenomenological thermodynamic theory proposed by Devonshire. Mechanical stress and electric field was calculated to change free energies of phases and shift MPB. The stable composition range of the phase, of which spontaneous strain and spontaneous polarization aligned to the direction of tensile stress or electirc field, was expanded.

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Temperature and Electric Field Effect on Proton Transfer in Adenine-thymine

  • Zhang, Guiqing;Xie, Shijie
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3532-3534
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    • 2014
  • In theoretical simulations of proton transfer in DNA, environmental factors nearly have not been considered. In our calculations, using QM/MM method on the basis of CP2K, proton transfer on adenine-thymine base pair is studied in water, at wide scope temperature, and under the external electric field. Our results indicate that the external electric field induces the proton transfer at room temperature, and its intensity and temperature have some effect on hole localization and proton transfer.

Retro-self-focusing and pinholing effect in a refractive index grating

  • Lee, Jae-Cheul
    • Journal of the Optical Society of Korea
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    • v.1 no.1
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    • pp.23-25
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    • 1997
  • In this paper we will show theoretically that a refractive index grating exhibits a retro-self-focusing effect and an accompanying pinholing effect under the Gaussian intensity distribution of an incident optical field. Those effects result from an effective wave number change of the medium due to the intense optical field.

The Effect of Field Practice of College Students on Career Search: Moderating Effect of Enterprising (대학생의 현장실습교육이 진로탐색에 미치는 영향 : 진취성의 조절효과)

  • Nam, Jae-Woo;Choi, Young-Keun
    • Journal of Convergence for Information Technology
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    • v.10 no.5
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    • pp.101-110
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    • 2020
  • In this study, the effect of field practice on the career exploration of college students was analyzed and the effect of adjusting the psychological variable, enterprising, was tested. To this end, the survey was conducted on university students who participated in the field practice. An analysis of 193 data showed that the effectiveness of field practice and the suitability of field practice companies were factors that increased the ability of college students to explore their career path. In addition, individual initiative was analyzed as a parameter, which strengthens the effectiveness of the practice and the suitability of the practical company on the ability of the career exploration. Universities should find quality practice companies and maintain the right field practice, and need to come up with pre-education programs that can improve career-related psychological capabilities.

Infrared spectroscopy of the effect of metal electrode on adsorbate under electric field: Electrochemical model study of CO on Pt(111) with ice film capacitor method in ultrahigh vacuum

  • Kang, Hani;Shin, Sunghwan;Park, Youngwook;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.143.2-143.2
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    • 2016
  • The influence of electric field on CO adsorbed on Pt(111) was investigated with reflection-absorption infrared spectroscopy (RAIRS) in ultrahigh vacuum system. The ice film capacitor method was used to apply electric field to the amorphous ice film with CO on Pt(111). Two systems were compared by measuring the change of the CO stretching vibrational mode under applied electric field; one is CO on Pt(111), and the other is CO buried inside an ice film on Pt(111). By comparing them, we were able to calculate the additional effect of adsorption of CO on Pt(111) on peak shift. The CO adsorbed on Pt(111) has shown larger peak shift than CO adsorbed with H2O when we applied stronger electric field. Additionally, the differences were observable when the applied electric field exceeds $1{\times}10V/m^8$.

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Study of monolithic 3D integrated-circuit consisting of tunneling field-effect transistors (터널링 전계효과 트랜지스터로 구성된 3차원 적층형 집적회로에 대한 연구)

  • Yu, Yun Seop
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.5
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    • pp.682-687
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    • 2022
  • In this paper, the research results on monolithic three-dimensional integrated-circuit (M3DICs) stacked with tunneling field effect transistors (TFETs) are introduced. Unlike metal-oxide-semiconductor field-effect transistors (MOSFETs), TFETs are designed differently from the layout of symmetrical MOSFETs because the source and drain of TFET are asymmetrical. Various monolithic 3D inverter (M3D-INV) structures and layouts are possible due to the asymmetric structure, and among them, a simple inverter structure with the minimum metal layer is proposed. Using the proposed M3D-INV, this M3D logic gates such as NAND and NOR gates by sequentially stacking TFETs are proposed, respectively. The simulation results of voltage transfer characteristics of the proposed M3D logic gates are investigated using mixed-mode simulator of technology computer aided design (TCAD), and the operation of each logic circuit is verified. The cell area for each M3D logic gate is reduced by about 50% compared to one for the two-dimensional planar logic gates.