• Title/Summary/Keyword: incoherent

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On Negative Imperatives in Korean

  • Han, Chung-hye;Lee, Chung-min
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2002.02a
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    • pp.59-68
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    • 2002
  • In this paper, we address two questions concerning negative imperatives in Korean: (i) what is the morpho-syntactic nature of mal in negative imperatives\ulcorner; and (ii) why is it impossible to form negative imperatives with short negation an\ulcorner We will argue that the clause structure of imperatives include a projection of deontic modality and a projection of imperative operator encoding illocutionary force, and that oaf is a lexicalization of long negation and deontic modality. We then propose that a negative imperative with short negation is ruled out because such construction maps onto incoherent interpretation which can be spelled out as I direct you to bring about a negative state or a negative event.

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Broadband DOA Estimation Techniques with Towed Hydrophone Array (견인 하이드로폰 배열을 이용한 수중에서의 광대역 신호 DOA 추정기법)

  • 강정원
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06c
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    • pp.465-468
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    • 1998
  • 본 논문은 천해 상에서 목표물로부터 방사되어 견인 이동되는 하이드로폰을 통하여 입사되는 광대역 신호에 대한 DOA (Direction-Of Arrival) 추정기법을 제안한다. 견인 배열 어레이를 이용하는 경우 고정된 위치의 배열 하이드로폰을 사용하는 경우와는 달리 움직임에 의한 도플러 주파수 천이 값이 발생하며 배열 상에 입사되는 광대역 신호는 각 주파수성분에 따라 서로 다른 고유 벡터 영역을 갖게 된다. 따라서 주파수 성분별로 처리하여 평균 공간 스펙트럼을 구하여 입사각을 추정하는 기존의 Incoherent 처리기법은 심각한 추정 오차를 발생시킨다. 본 논문에서는 이러한 문제점을 해결하기 위하여 각 주파수 성분에 대한 고유한 벡터영역들을 Coherent 변환과정을 거쳐서 통합된 벡터영역으로 변환하여 공간 스펙트럼을 추정하고 이를 통하여 입사각을 추출한다. 시뮬레이션 결과를 통하여 Cherent 처리기법을 이용한 입사각 추정상의 우수한 성능을 확인하였다.

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Matched Field Processing: Ocean Experimental Data Analysis Using Feature Extraction Method (실 해상 실험 데이터를 이용한 정합장 처리에서의 특성치 추출 기법 분석)

  • Kim Kyung Seop;Seong Woo Jae;Song Hee Chun
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.1E
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    • pp.21-27
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    • 2005
  • Environmental mismatch has been one of important issues discussed in matched field processing for underwater source detection problem. To overcome this mismatch many algorithms professing robustness have been suggested. Feature extraction method (FEM) [Seong and Byun, IEEE Journal of Oceanic Engineering, 27(3), 642-652 (2002)] is one of robust matched field processing algorithms, which is based on the eigenvector estimation. Excluding eigenvectors of replica covariance matrix corresponding to large eigenvalues and forming an incoherent subspace of the replica field, the processor is formulated similarly to MUSIC algorithm. In this paper, by using the ocean experimental data, processing results of FEM and MVDR with white noise constraint (WNC) are presented for two levels of multi-tone source. Analysis of eigen-space of CSDM and FEM performance are also presented.

Organic Photorefractive Composites for Optical Information Processing

  • Oh, Jin-Woo;Hwang, Ui-Jung;Choi, Chil-Sung;Kim, Nak-Joong
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.164-164
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    • 2006
  • Polymeric photorefractive materials exhibit two attractive features, the large refractive index modulation (up to the order of $10^{-2}$) and the optical erasabilility of recorded holographic information. These advantages make the organic photorefractive materials to become candidates for optical data processing, e.g., pattern recognition and fingerprint verification. In this work, we demonstrate optically controlled SLMs using photorefractive composite. An incoherent image imposed in Xe-lamp light was converted into a coherent image.

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A Study on the Optical Character Recognition using Optical Correlators Computer (광상관기를 이용한 컴퓨터용 광문자인식에 관한 연구)

  • 박현철;송우영;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.9 no.4
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    • pp.179-183
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    • 1984
  • Only K=$log_2$N reference patterns called principal components are sufficient to identify one out of N characters, calculated by computer and fablicated. An incogerent optical correlator is used for correlation coefficient measurements and it is shown that that this method has better discrimination ability that analog measuments using matched filter.

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Dynamic Range Improvement of IM-DD Optical Link using Dual-Wavelength Dual-Parallel Modulation

  • Li, Xianghua;Yang, Chun;Zhou, Zhenghua;Chong, Yuhua
    • Journal of the Optical Society of Korea
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    • v.18 no.4
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    • pp.330-334
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    • 2014
  • In this paper, we present an incoherent dual-parallel modulation linearized optical link employing two different optical wavelengths. Comparing with previous dual-parallel modulation, this linearization method prevents the recreation of distortion products and can be readily implemented. Furthermore, a dual-wavelength dual-parallel modulation linearized optical link constructed with the commercially available devices is experimentally demonstrated with a spurious-free dynamic range of $122.5dB.Hz^{4/5}$. More than 25 dB suppression of the intermodulation distortion, 15.6 dB improvement of spurious-free dynamic range and 1.5 dB improvement of compression dynamic range are achieved after linearization.

Localization of coherent/incoherent sources-simulation and experiment (독립/비독립 음원의 위치 탐지 방법)

  • 김시문;김양한
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.10a
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    • pp.86-91
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    • 1995
  • 음원의 위치를 찾는 문제에 있어서 비독립 음원들이 존재하는 경우, 근접장에서는 음원으로부터 나오는 파형을 평면파로 가정할 수 없고 구면파로 가정해야 하며, 여러개의 비독립 음원이 존재한다고 가정하여 각각의 음원의 위치를 변화시켜 가면서 MUSIC파워를 계산하여야 한다. 실제 음원의 갯수보다 가정한 음원의 갯수가 작으면 정확한 음원의 위치를 가르키지 못하며 MUSIC 파워 값도 작다. 실제 음원의 갯수와 가정한 음원의 갯수가 같으면 정확한 음원의 위치를 가르치며 MUSIC 파워 값이 크게 얻어진다. 실제 음원의 갯수보다 가정한 음원의 갯수가 큰 경우 실제의 음원의 위치를 포함하여 다른 음원의 위치를 얻을 수 있으나 그 음원의 세기는 무시할 정도로 작다. 즉 실제 음원의 갯수보다 많은 수의 음원을 가정하여 음원을 탐지할 수 있다. 일반 음장 즉 독립 음원과 비독립 음원이 공존하는 경우 실제의 음원의 갯수만큼 가정한다면 음원이 위치를 찾을 수 있다.

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A study on the Theoretical Resolution of Conoscopic Holography (Conoscopic holography의 이론적인 해상도에 대한 연구)

  • Kim, Soo-Gil;Ko, MyungSook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.8
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    • pp.1-5
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    • 2014
  • Conoscopic holography, which consists of two circular polarizers and an uniaxial crystal, is incoherent holographic technology for three-dimensional display and non-contact diagnosis. In this paper, we derive the longitudinal and lateral intensities from point-source hologram made by conoscopic holography. Also, the longitudinal and lateral resolutions of conoscopic holography will be obtained from the longitudinal and lateral intensities, respectively, according to Rayleigh criterion.

Design & Analysis of an Error-reduced Precision Optical Triangulation Probes (오차 최소화된 정밀 광삼각법 프로브의 해석 및 설계)

  • Kim, Kyung-Chan;Oh, Se-Baek;Kim, Jong-Ahn;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.411-414
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    • 2000
  • Optical Triangulation Probes (OTPs) are widely used for their simple structure. high resolution, and long operating range. However, errors originating from speckle, inclination of the object, source power fluctuation, ambient light, and noise of the detector limit their usability. In this paper, we propose new design criteria for an error-reduced OTP. The light source module for the system consists of an incoherent light source and a multimode optical fiber for eliminating speckle and shaping a Gaussian beam Intensity profile. A diffuse-reflective white copy paper, which is attached to the object, makes the light intensity distribution on the change-coupled device(CCD). Since the peak positions of the intensity distribution are not related to the various error sources, a sub-pixel resolution signal processing algorithm that can detect the peak position makes it possible to construct an error-reduced OTP system

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Enhanced Photodetection with Hot Electrons in Graphene-mediated Plasmonic Nanostructure

  • Kim, Jeong Hyeon;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.408-408
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    • 2014
  • Graphene has received attention with its high electron mobility and visual transparency as a promising material for optoelectronic and photonic applications. Combination of graphene and conducting nanostructures i.e. plasmonic structures has recently been researched for enhancing light-matter interaction and overcoming diffraction limit of light. Here we show enhanced photodetection of incoherent visible light with graphene-mediated plasmonics. Gold nanoparticles fabricated by focused ion beam was used as an active element of photodetection and graphene was utilized as an interfacing material between nanostructures and electrodes. Hot electrons generated upon plasmon decay within nanoparticles pass over the potential barrier between nanostructure and graphene and give rise to a photocurrent with built-in electric field. We report 76.7% enhancement of photocurrent under resonant irradiation of fiber-coupled halogen lamp compared to the case without light illumination. We showed wavelength-dependent current response arisen from plasmonic nanostructure, providing a good agreement with theoretical calculation.

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