• Title/Summary/Keyword: optical parameter

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Design of foot parameter measurement system in 3D Point cloud (3D 점군 데이터에서의 발 고유 변인 검출 시스템 설계)

  • Yun, Jeongrok;Kim, Un Yong;Kim, Hoemin;Chun, Sungkuk
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2021.07a
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    • pp.695-696
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    • 2021
  • 최근 다양한 연령층과 직업군들 사이에서 기능성 신발에 대한 관심이 증대되고 있다. 그러나 기능성 신발 및 맞춤형 신발은 높은 가격대와 긴 제작 시간이 필요하다. 이러한 문제점은 3D 스캐너 도입으로 해결이 가능하나, 정확한 발 형상 측정이 가능한 3D 스캐너는 고가의 장비이기 때문에 매장별 보급이 어렵다. 본 논문은 기능성 신발의 보급을 위하여 저가형 3D 스캐너에서 정확한 발 고유 변인을 측정할 수 있는 시스템에 대해 서술한다. 이를 위해 이를 위해 저가형 Depth Camera를 이용한 저가형 3D 스캐너의 발 형상 3D 점군 데이터를 2차원으로 변형하고, 발 형태를 감싸는 최소 사각형(Min Area Rect)를 형성하여 발 안쪽점 및 발 가쪽점을 추정한다. 생성된 최소 사각형과 발 안쪽점 및 발 가쪽점 등은 발 고유 변인 측정의 기준이 된다. 실험 결과에서는 측정 기준을 이용하여 발 고유 변인인 발 길이, 발 너비, 발꿈치 너비, 발꿈치에서 발안쪽점 및 발 가쪽점 길이 등 5가지 고유 변인을 측정하는 것을 보여준다.

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A study on the Convergence of Iterative Fourier Transform Algorithm for Optimal Design of Diffractive Optical Elements (회절광학소자의 최적 설계를 위한 Iterative Fourier Transform Algorithm의 수렴성에 관한 연구)

  • Kim, Hwi;Yang, Byung-Choon;Park, Jin-Hong;Lee, Byoung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.5
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    • pp.298-311
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    • 2003
  • Iterative Fourier transform algorithm, (IFTA) is tile iterative numerical algorithm for the design of the diffractive optical elements (DOE), by which the phase distribution of a DOE converges on a local optimal solution. The convergence of IFTA depends on several factors 3s initial phase distribution, the structure of the degree of freedom on the observation plane, and the values of internal parameters. In this paper, we analyze tile dependence of the convergence of IFTA on an internal parameter of IFTA, the relaxation parameter, and propose a new hybrid scheme of genetic algorithm and IFTA to obtain more accurate solution.

Wideband WDM Transmission through the Power Symmetry Method in the Mid-Span Spectral Inversion (Mid-Span Spectral Inversion을 이용한 광 펄스 왜곡의 보상에서 전력 대칭을 통한 광대역 WDM 전송)

  • 이성렬;이윤현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.7
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    • pp.1157-1166
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    • 2001
  • In this paper, we investigated the degree of compensation for optical pulse shape distortion due to both chromatic dispersion and SPM(self phase modulation) in high speed optical transmission system with dispersion shift fiber. We adopted the power symmetric MSSI(mid-span spectral inversion) as compensation method. We used EOP(eye-opening penalty) parameter in order to evaluate the compensation efficiency of distorted optical pulse. We evaluated input signal power range being able to maintain stable reception performance in the case of various chirp parameter of modulated optical pulse. And, in order to verify the applicable to wideband WDM system, we evaluated the wavelength range being able to maintain stable reception performance through the EOP calculation of various dispersion coefficient of first fiber D$\_$11/. We showed that proposed MSSI is effective compensation method to down chirped optical pulse transmission rather than up chirped optical pulse transmission in anomalous dispersion range. And we showed that this method have possibility of relative high power transmission and wideband transmission in WDM system.

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Asian Dust Measurement and Analysis of Optical Parameter using ACA Lidar, 2002 spring (연속측정 라이다에 의한 2002년 황사의 측정과 광학적 파라메터의 해석)

  • 김진환;박찬봉;이주희
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.118-119
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    • 2002
  • 매년 봄 한반도 영향을 주는 황사는 오랫동안 이 지역의 자연환경에 많은 영향을 주고 있다. 본 라이다 센터에서는 1995년부터 라이다를 사용하여 황사를 포함하는 에어로졸을 관측하였고 1999년 10월부터는 성층권을 관측할 수 있는 다파장 에어로졸 라이다(MWA Lidar, 1064/532/355)를, 그리고 2002년 2월부터는 대류권을 관측하는 자동운전 에어로졸 라이다(ACA Lidar, 532)를 운전하여 집중적으로 황사를 관측하여 많은 관련 데이터를 생산하였다. (중략)

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Driving-Condition-Dependent Optical Transmission Characteristics of an STN LCD (구동조건에 따른 STN LCD의 광투과 특성)

  • 고형일;정태혁;이상찬;윤태훈;김재창
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.10
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    • pp.35-42
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    • 1995
  • In this paper the driving-condition-dependent optical transmission characteristics of an STN LCD are studied. The optical transmission properties are measured for the applied voltage waveform is varied. Also, the optimum ranges of the M signal frequency and the frame frequency are investigated. An LCD is modeled by the equivalent circuit to study the effect of the parameter variation on the frequency response.

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Gaussian apodization technique in holographic demultiplexer based on photopolymer volume grating (포토폴리머 부피형 회절격자를 이용한 홀로그래픽 역다중화기의 가우시안 아포다이징)

  • Duc-Dung Do;An Jun Won;Kim Nam;Lee Gwon Yeon
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.246-247
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    • 2003
  • In recent years, soaring traffic volumes over optical communications networks lead to the rapid advances in information communications equipments. In backbone communications networks, there has been an advance in high-density transmission through DWDM, which can simultaneously transmit numerous signals with different wavelengths. When the channel spacing is narrower, the cross-talk between channels an important parameter that guarantees to the high performance of a whole system, becomes critical. (omitted)

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Lidar Measurement of Asian Dust and Analysis of Optical Parameter using 1064 nm, 532 nm Wavelength (1064 nm, 532 nm 파장을 이용한 황사의 라이다 관측과 광학적 파라메타의 해석)

  • 김진환;박찬봉;이주희
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.214-215
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    • 2003
  • 2002년 수원상공의 황사를 라이다를 이용하여 관측하고, 이의 광학적 특성을 보고한다. 기상청의 1월부터 5월까지의 황사보고는 16일로 예년에 비해 많이 발생하였고, 특히 11년만에 11월에 황사가 발생하여 사회적으로 많은 관심이 되었다. 본 라이다센터에서는 2002년 3월부터 대류권을 관측하는 자동운전 에어로졸 라이다(ACA Lidar, 532 nm)를 운전하여 집중적으로 황사를 관측하였고 2002년 10월부터는 1064 nm 파장을 추가하여 많은 관련 데이터를 생산하였다. (중략)

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A Study of PMD Characteristic in Single Mode Optical Fiber (단일모드 광섬유에서의 편광모드분산 특성에 관한 연구)

  • 이청학;김성탁;김기대;박대희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.201-204
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    • 1999
  • Polarization mode dispersion (PMD) restrict the bend-width of single mode optical filer, and it is important parameter in the optical fiber having long-length. Although fiber has perfect circular symmetry, fiber bending, twisting and laws governing manufacture cause additional Polarization mode dispersion. The effect of polarization mode dispersion in general single mode fiber of long length is discussed in this paper. Measurement of PMD with random mode coupling were conducted in two kind of fibers using different laws governing manufacture and interferometric method.

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Performance Evaluation of Low-cost Optical Components used for Measuring the Optical Density and Concentration of Particulate Matter(PM) (입자상물질의 광학밀도 및 농도측정에 적용된 저가형 광학 부품의 성능평가)

  • Baik, Young Jo;Hong, Terki;Hwang, Cheol Hong;Park, Seul Hyun
    • Journal of the Korean Society of Safety
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    • v.31 no.5
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    • pp.1-6
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    • 2016
  • The performance of a set of low-cost optical components used for measuring the optical density of PM particles was evaluated in the present study. To this end, the set of low-cost optical components was replaced with that of general optical components used to measure the PM optical density under identical experimental conditions. The optical densities measured from the set of general optical components were then compared to those obtained from the set of low-cost optical components. While the optical density is measured, another key parameter, the dimensionless extinction constant of PM particles (which is needed to optically measure the PM concentration) was also determined in the present study. The experimental results indicate that the optical density and PM concentration measurements performed by low-cost optical components are feasible, producing trackable variations in the OD and concentrations compared to values obtained from the set of general optical components.

A study on underwater optical wireless communication link capability in the Bay of Bengal

  • Sathyaram, V.;Prince, Shanthi;Vedachalam, N.
    • Ocean Systems Engineering
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    • v.8 no.1
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    • pp.33-39
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    • 2018
  • The paper presents a numerical underwater channel model developed in MATLAB for estimating the optical link budget between a light emitting diode (LED) based optical transmitter and a photo diode (PD) receiver when operated in the harbor, coastal and deep waters locations in the Bay of Bengal. The water samples are collected at different locations in the Bay of Bengal using a water sampler during an offshore research cruise. The optical attenuation, the main inherent parameter determining the range of the optical communication link is identified for the different waters using an underwater irradiance measurement system in the laboratory. The identified parameters are applied to the numerical model and found that a 10 W LED and a photo diode based system can provide the optical budget required for a horizontal underwater communication range of about 0.5, 14 and 35 m in the harbor, coastal and deep waters locations respectively. By increasing the transmitter power to 50 W, the operating range of the communication link could be increased up to 53 m in deep water locations in the Bay of Bengal.