• 제목/요약/키워드: Interference Pattern

검색결과 416건 처리시간 0.029초

안정화된 간섭계와 FFT를 이용한 표면 측정 (Surface profile measurement with FFT method and stabilized interferometer)

  • 류진;김현수;박종락;김진태
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.269-273
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    • 2004
  • The moduled interferometer with waveplates, polarizing beam splitter, etc. for four phase shifted interference patterns was stabilized with the and Fast Fourier Transform (FFT) method was used to investigate the surface profile measurement from the interferenece pattern from Twyman-Green interferometer using a mathcad.

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Prioritized Channel Allocation for Cellular Mobile Systems Using Simulated Annealing

  • Chang, Kun-Nyeong
    • 한국경영과학회지
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    • 제23권3호
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    • pp.37-47
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    • 1998
  • Under the cutoff priority discipline, the prioritized channel allocation problem is formulated, which minimizes the overall blocking probability while ensuring the co-channel interference constraints. To deal with the problem more conveniently, the concept of pattern is used. A simulated annealing approach is applied to the problem, and computational experiments show that a high-quality solution is obtained.

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근접장 기록을 위한 디스크의 광학적 특성 (Optical characteristics of discs for near-filed recording)

  • 민철기;박노철;박경수;박영필
    • 정보저장시스템학회논문집
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    • 제5권2호
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    • pp.64-69
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    • 2009
  • In this paper, we investigate field distribution and interference pattern in the exit pupil and in the focal region. Also, we compare with metal and dielectric substrate for near-field recording. To obtain field distribution, we use modified vector diffraction theory and Zernike Polynomials. Finally, we design and optimize refractive index and thickness of disk for near-field surface recording and cover-layer incident recording.

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Microscopic Studies and Simulations of Bloch Walls in Nematic Thin Films

  • Park, Jung-Ok;Zhou, Jian;Srinivasarao, Mohan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.493-495
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    • 2005
  • The director profiles of the Bloch walls are directly visualized using fluorescence confocal polarizing microscopy. Both pure twist Bloch walls and diffuse Bloch walls are analyzed. Polar anchoring energy was measured from optical simulation of the transmitted light interference pattern or the fluorescence intensity profile of a pure twist wall..

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2-beam Coupling 방법을 이용한 광 고분자 형광 패턴 형성 (Fluorescent Pattern Generation on the Fluorescent Photopolymer with 2-beam Coupling Method)

  • 김윤정;김정훈;심보연;이명규;김은경
    • 한국광학회지
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    • 제21권1호
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    • pp.6-11
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    • 2010
  • 아크릴레이트계 모노머를 사용한 최적화 된 포토폴리머에 안트라센 형광폴리머를 첨가하여 형광 특성을 가지는 포토폴리머를 제조하고, 514 nm 레이저를 이용하여 2-beam coupling 방법으로 형광 포토폴리머 필름 위에 회절격자를 형성하였다. 기록 시작 후 30초 이내에 선명한 fluorescent line pattern 이 형성되었으며, 회절격자 형성 뒤, 패턴이 형성된 부분에서 형광 세기의 증가가 관찰되었다. 기록 시 간섭 빔 앞에 mask pattern 을 이용하여 $50\;{\mu}m$ gap electrode 패턴을 형성하였다. 이 때 형성된 패턴은 micron scale gap패턴 안에 회절격자로부터 생성된 submicron scale의 grating line을 보였다. 이는 beam의 광 고분자 film 표면에 대한 각도($3.6^{\circ}$, $15^{\circ}$), 패턴에 사용된 광 고분자의 굴절률 등으로부터 Bragg's equation 을 사용하여 계산된 이론적인 grating 간격 ($0.6\;{\mu}m$) 과 오차범위 안에서 일치 하였다.

3차원 동영상을 구현하기 위한 실시간 홀로그램의 제작 (Fabrication of Real-Time Hologram for the Implementation of 3-D Moving Picture)

  • 박세준;배장근김수중
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.977-980
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    • 1998
  • A real-time holography system using LCD with CCD camera is proposed. In this system, the rainbow hologram is used since it can be reconstructed by white light source. And to record on CCD camera, a kind of in-line holography method is used to widen the width of the fringe pattern. The interference fringe pattern by proposed system is detected with CCD camera and transferred to the LCD A 3-dimensional image is reconstructed when a white light source illuminates the LCD. So it can represent 3 dimensional moving images at real-time. In this paper, to confirm the usefulness of the proposed method, the reconstructed image by holographic film is compared to the same reconstruct image by LCD. In the recording of the interferenced processing, the optimal ratio of the reference and object beam intenstiy is also investigated.

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X-ray PIV Measurements of Velocity Field of Blood Flows

  • 이상준
    • 순환기질환의공학회:학술대회논문집
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    • 순환기질환의공학회 2006년도 춘계학술강연회
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    • pp.28-36
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    • 2006
  • The x-ray PIV method was improved for measuring quantitative velocity fields of real blood flows using a coherent synchrotron x-ray source. Without using any contrast media or seeding particles, this method can visualize flow pattern of blood by enhancing the phase-contrast and interference characteristics of blood cells based on a synchrotron x-ray imaging mechanism. The enhanced x-ray images were achieved by optimizing the sample-to-scintillator distance, the sample thickness, and hematocrit. The quantitative velocity fields of blood flows inside opaque tubes were obtained by applying a 2-frame PIV algorithm to the x-ray images of the blood flows. The measured velocity field data show typical features of blood flows such as the yield stress effect. The non-Newtonian flow characteristics of blood flows were analyzed using the x-ray PIV method and the experimental results were compared with hemodynamic models.

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전자 스페클 간섭법과 유한요소법을 이용한 면내변형의 측정에 관한 연구 (A Study on the Measurement of In-plane Deformations by using Electronic Speckle Pattern Interferometry and Finite Element Method)

  • 강형수;조기현;김홍석;정형길
    • 한국산업융합학회 논문집
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    • 제5권3호
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    • pp.187-192
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    • 2002
  • In-plane ESPI(Electronic Speckle Patten Interferometry)was devised to measure in~plane defamation and rotation of a specimen with laser in this study. The conventional measuring methods of surface deformations such as the strain gauge have many demerits because they are contact and point-to-point measuring ones. But that ESPI is noncontact, nondestructive and whole field measuring method can overcome previous disadvantages. We used ESPI which is sensitive to in-plane displacement for measuring in-plane deformations of a disk. First of all, the system calibration was done due to an in-plane rotation before getting deformations of a disk. Finally we showed good agreement between theexperiment results and those of the FEA(Finit Element Analysis).

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SYNTACTIC 패턴인식에 의한 생체신호처리 (Biological signal processing using syntactic pattern recognition)

  • 김용만;김정훈;정희교;이명호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.1284-1287
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    • 1987
  • A method of quantitative electrocardiogram analysis, based on concepts drawn from syntactic pattern recognition theories, is described. The algorithm can be used for removing the Interference noises and base line drift as a filter function, and for reducing the number of points representing the digitized ECG waveform. The Parsing is performed with simple finite state automata inferred by experiments and suitable to be updated during experiment execution. Two parameters are utilized for defining the noise and these make the algorithm flexible. The examples for testing the algorithm is real ECG waveforms with noise. Some experimental results lire presented.

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X-ray PIV Measurements of Velocity Field of Blood Flows

  • Lee, Sang-Joon;Kim, Guk-Bae
    • International Journal of Vascular Biomedical Engineering
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    • 제4권1호
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    • pp.1-8
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    • 2006
  • The x-ray PIV method was improved for measuring quantitative velocity fields of real blood flows using a coherent synchrotron x-ray source. Without using any contrast media or seeding particles, this method can visualize flow pattern of blood by enhancing the phase-contrast and interference characteristics of blood cells based on a synchrotron x-ray imaging mechanism. The enhanced x-ray images were achieved by optimizing the sample-to-scintillator distance, the sample thickness, and hematocrit. The quantitative velocity fields of blood flows inside opaque tubes were obtained by applying a 2-frame PIV algorithm to the x-ray images of the blood flows. The measured velocity field data show typical features of blood flows such as the yield stress effect. The non-Newtonian flow characteristics of blood flows were analyzed using the x-ray PIV method and the experimental results were compared with hemodynamic models.

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