• Title/Summary/Keyword: 2-Phase

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Ideal Phase map Extraction Method and Filtering of Electronic Speckle Pattern Interferometry (전자 스페클 간섭법에서의 이상적인 위상도 추출과 필터링 방법)

  • 강영준;이주성;박낙규;권용기
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.12
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    • pp.20-26
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    • 2002
  • Deformation phase can be obtained by using Least-Square fitting. In extraction of phase values, Least-Square Fitting is superior to usual method such as 2, 3, 4-Bucket Algorithm. That can extract almost noise-free phase and retain 2 $\pi$ discontinuities. But more fringes in phase map, 2 $\pi$ discontinuities are destroyed when that are filtered and reconstruction of deformation is not reliable. So, we adapted Least-Square fitting using an isotropic window in dense fringe. Using Sine/cosine filter give us perfect 2 $\pi$ discontinuities information. We showed the process and result of extraction of phase map and filtering in this paper.

Variation of Dielectric Properties and Phase Stabilities with Substitution of A-Site in $Pb(Zn_{0.6}Mg_{0.4})_{1/3}Nb_{2/3}O_3$[PZMN] System ($Pb(Zn_{0.6}Mg_{0.4})_{1/3}Nb_{2/3}O_3$ [PZMN] 계에서 A-자리 치환에 따른 상안정화 및 유전 특성 변화)

  • 김봉철;김정주;김남경;조상희
    • Journal of the Korean Ceramic Society
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    • v.33 no.10
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    • pp.1131-1137
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    • 1996
  • The dielectric properties and phase stabilities of Pb(Zn0.6Mg0.4)1/3Nb2/3O3 [PZMN]system were investigated into substitution of A-site with Ba, Sr and Ca ions. The A-site substitutions led to the complexity of components of perovskite phase and then DPT coefficient increased. The A-site substitutions of Ba or Sr ion perovskite single phase could be easily formed by columbite process due to increase of perovskite phase stability. The variation of lattice parameters in specimen obeyed Vegard's law and curie temperature and dielectric constant of specimen decreased linearly. But Ca substitution led to perovskite phae instability. The lattice parameter dielectric constant and curie temperature of specimens drasticaly decreased with formation of pyrochlore phase.

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Analysis of The Generating Torque Characteristics of 2-Phase lnduction Motor in Phase Control. (이상유도전동기의 립상제어시 발생토오크에 대한 해석)

  • 원종수;장도현
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.37 no.5
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    • pp.289-297
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    • 1988
  • In this paper, the analysis of a generating torque characteristics of 2-phase induction motor driven with the phase control method is presented. The generating torque equations which represent average torque and pulsating torque are derived from the elementary machine model. The calculating equations which can get the values of average torque and pulsating torque is expressed by the parameters of the equivalent circuit of 2-phase induction motor. According to the calculating equations, these performance characteristics are investigated under various conditions. Finally, a strategy to eliminate non-linearity and pulsating torque generated in driving 2-phase induction motor with the phase control method is presented.

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A study on the phase transition characteristics of the $Ba(La_{1/2} Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ ceramics ($Ba(La_{1/2} Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ 세라믹의 상전이 특성에 관한 연구)

  • 류기원;배선기;박인길;이영희
    • Electrical & Electronic Materials
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    • v.8 no.2
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    • pp.190-195
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    • 1995
  • Temperature dependences of the dielectric constant K(T), remanent polarization $P_{r}$, (T), effective birefringence overbar .DELTA.n(T), transmitted light intensity and quadratic electro optic coefficient R(T) of the two-stage sintered xBa(L $a_{1}$2/N $b_{1}$2/) $O_{3}$-(1-x)Pb(Z $r_{y}$ $Ti_{1-y}$) $O_{3}$(x=0.085, 0.09, 0.40.leq.y.leq.0.70) ceramics were investigated. Increasing the PbZr $O_{3}$ contents, the crystal structure of a specimen was changed from a tetragonal phase to a rhombohedral and cubic phase, and the phase transition was showed a diffuse phase transition(DPT) characteristics. In the compositions which located on the PE-FE phase boundary, the discrepancy was observed between the Curie temperature and temperature which a microscopic polarization and effective birefringence were disappeared.red.d.

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Novel PWM Methods for Two-Leg and Four-leg Two-Phase Inverter Fed Two-Phase Induction Motor (2상 유도전동기 구동 2상 인버터를 위한 새로운 PWM제어방식 I - 2-레그 타입 및 4-레그 타입의 경우 -)

  • Jang Do-Hyun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.4
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    • pp.331-338
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    • 2005
  • In this paper the novel pulsewidth modulation(PWM) technique for the two-leg and four-leg two-phase inverter is proposed. The conventional space vector PWM technique for two-phase inverter was complex. The proposed PWM for two-leg inverter, which is used by sinusoidal PWM method, is simpler than the conventional SVPWU technique. Also, a simple PWM technique for four-leg two-phase inverter is proposed. Such PWM technique is based on PWM technique for two-leg inverter. Practical verification of theoretical predictions is presented to confirm the capabilities of the new techniques.

A Fast Locking Phase-Locked Loop using a New Dual-Slope Phase Frequency Detector and Charge Pump Architecture (위상고정 시간이 빠른 새로운 듀얼 슬로프 위상고정루프)

  • Park, Jong-Ha;Kim, Hoon;Kim, Hee-Jun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.5
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    • pp.82-87
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    • 2008
  • This paper presents a new fast locking dual-slope phase-locked loop. The conventional dual-slope phase-locked loop consists of two charge pumps and two phase-frequency detectors. In this paper, the dual-slope phase-locked loop was achieved with a charge pump and a phase-frequency detector as adjusting a current of the charge pump according to the phase difference. The proposed circuit was verified by HSPICE simulation with a $0.35{\mu}m$ CMOS standard process parameter. The phase locking time of the proposed dual-slope phase-locked loop was $2.2{\mu}s$ and that of the single-slope phase-locke loop was $7{\mu}s$.

A Review on Deep-learning-based Phase Unwrapping Technique for Synthetic Aperture Radar Interferometry (딥러닝 기반 레이더 간섭 위상 언래핑 기술 고찰)

  • Baek, Won-Kyung;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.38 no.6_2
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    • pp.1589-1605
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    • 2022
  • Phase unwrapping is an essential procedure for interferometric synthetic aperture radar techniques. Accordingly, a lot of phase unwrapping methods have been developed. Deep-learning-based unwrapping methods have recently been proposed. In this paper, we reviewed state-of-the-art deep-learning-based unwrapping approaches in terms of 1) the approaches to predicting unwrapped phases, 2) deep learning model structures for phase unwrapping, and 3) training data generation. The research trend of the approaches to predicting unwrapped phases was introduced by categorizing wrap count segmentation, phase jump classification, phase regression, and deep-learning-assisted method. We introduced the case studies of deep learning model structure for phase unwrapping, and model structure optimization to relate the overall phase information. In addition, we summarized the research trend of the training data generation approaches in the views of phase gradient and noise in the main. And the future direction in deep-learning-based phase unwrapping was presented. It is expected that this paper is used as guideline for exploring future direction of deep-learning-based phase unwrapping research in Korea.

The Characteristics of MMIC Phase Shifter with Lange Coupler (Lange 커플러를 이용한 MMIC 위상변위기 특성)

  • 정명득;박동철
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.2
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    • pp.104-110
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    • 2003
  • This paper proposed a simple 180$^{\circ}$ MMIC phase shifter for wideband application. The phase shifter simply consists of a Lange coupler and two GaAs PIN diodes. The measured performance of the phase shifter in the 2 to 6 GHz band shows a maximum phase error of less than 13$^{\circ}$, maximum 3.2 dB insertion loss, and minimum 6.3 dB return loss.

Encryption and decryption of binary data with 2-step phase-shifting digital interferometry (2-step 위상 천이 디지털 간섭계를 이용한 이진 데이터 암호화 및 복호화)

  • Byeon, Hyeon-Jung;Gil, Sang-Geun;Ha, Seung-Ho
    • Proceedings of the Optical Society of Korea Conference
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    • 2006.02a
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    • pp.335-336
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    • 2006
  • We propose a method of encryption and decryption of binary data using 2-step phase-shifting digital interferometry. This technique reduces the number of interferograms in the phase-shifting interferometry. The binary data has been expressed with random code and random phase. We remove the dc-term of the phase-shifting digital interferogram to restore the original binary data. Simulation results shows that the proposed technique can be used for binary data encryption and decryption.

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Phase Changes of Vanadium Oxide Thin Films (산화 바나듐 박막의 상변화)

  • 선우진호;신인하;고경현;안재환
    • Journal of the Korean institute of surface engineering
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    • v.25 no.6
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    • pp.293-298
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    • 1992
  • Various vanadium-oxide thin films were deposited by e-beam and thermal evaporation of V2O5, V2O3, and VO2 powders. Films with thickness of $2000\AA$ were subjected to annealing at $300^{\circ}C$~$450^{\circ}C$ in N2 atmosphere for the crystallization and desification purposes. For the films deposited from V2O5 and VO2 sources, sources, Magneli (VnO2n-1$ 4\leq$ $n\leq$ 8) and VO2 phase appeared at $300^{\circ}C$, respectively, but VO2 phase also transformed into Magneli phase at $450^{\circ}C$ by severe reduction. On the contrary, VO2/VO mixed phases resulted from congruent evaporation of V2O3 unchanged after the same annealing treatment due to the balanced reduction and oxidation of VO2 and VO whcih have different equilibrium O2 pressures. It is suggested that the annealing in the controlled oxidation atmosphere or the deposition using mixed oxide sources are necessary to get the film containing VO2 phase.

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