• 제목/요약/키워드: External Illumination

검색결과 70건 처리시간 0.026초

실시간 영상감시 시스템 개발 (A Development of Video Monitoring System on Real Time)

  • 조현섭
    • 한국산학기술학회논문지
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    • 제8권2호
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    • pp.240-244
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    • 2007
  • 본 논문에서는 실시간으로 눈을 검출하고 추적하는 새로운 방법을 제안하고자 한다. 기존의 능동적 적외선을 이용한 눈 검출 및 추적 방법은 외부의 조명에 매우 민감하게 반응하는 문제점을 가지고 있으므로, 본 논문에서는 적외선 조명을 이용한 밝은 동공 효과와 전형적인 외형을 기반으로 한 사물 인식 기술을 결합하여 외부 조명의 간섭으로 밝은 동공 효과가 나타나지 않는 경우에도 견실하게 눈을 검출하고 추적 할 수 있는 방법을 제안한다. 눈 검출과 추적을 위해 SVM과 평균 이동 추적방법을 사용하였고, 적외선 조명과 카메라를 포함한 영상 획득 장치를 구성하여 제안된 방법이 효율적으로 다양한 조명하에서 눈 검출과 추적을 할 수 있음을 보여 주었다.

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다양한 조명하에서 실시간 눈 검출 및 추적 (Real-Time Eye Detection and Tracking Under Various Light Conditions)

  • 박호식;배철수
    • 한국정보통신학회논문지
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    • 제8권2호
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    • pp.456-463
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    • 2004
  • 본 논문에서는 다양한 조명하에서 실시간으로 눈을 검출하고 추적하는 새로운 방법을 제안하고자 한다. 기존의 능동적 적외선을 이용한 눈 검출 및 추적 방법은 외부의 조명에 매우 민감하게 반응하는 문제점을 가지고 있으므로, 본 논문에서는 적외선 조명을 이용한 밝은 동공 효과와 전형적인 외형을 기반으로 한 사물 인식 기술을 결합하여 외부 조명의 간섭으로 밝은 동공 효과가 나타나지 않는 경우에도 견실하게 눈을 검출하고 추적 할 수 있는 방법을 제안한다. 눈 검출과 추적을 위해 SVM과 평균 이동 추적방법을 사용하였고, 적외선 조명과 카메라를 포함한 영상 획득 장치를 구성하여 제안된 방법이 효율적으로 다양한 조명하에서 눈 검출과 추적을 할 수 있음을 보여 주었다.

Fabrication and performance evaluation of ultraviolet photodetector based on organic /inorganic heterojunction

  • Abdel-Khalek, H.;El-Samahi, M.I.;Salam, Mohamed Abd-El;El-Mahalawy, Ahmed M.
    • Current Applied Physics
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    • 제18권12호
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    • pp.1496-1506
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    • 2018
  • Organic/inorganic ultraviolet photodetector was fabricated using thermal evaporation technique. Organic/inorganic heterojunction based on thermally evaporated copper (II) acetylacetonate thin film of thickness 200 nm deposited on an n-type silicon substrate is introduced. I-V characteristics of the fabricated heterojunction were investigated under UV illumination of intensity $65mW/cm^2$. The diode parameters such as ideality factor, n, barrier height, ${\Phi}_B$, and reverse saturation current, $I_s$, were determined using thermionic emission theory. The series resistance of the fabricated diode was determined using modified Nord's method. The estimated values of series resistance and barrier height of the diode were about $0.33K{\Omega}$ and 0.72 eV, respectively. The fabricated photodetector exhibited a responsivity and specific detectivity about 9 mA/W and $4.6{\times}10^9$ Jones, respectively. The response behavior of the fabricated photodetector was analyzed through ON-OFF switching behavior. The estimated values of rise and fall time of the present architecture under UV illumination were about 199 ms and 154 ms, respectively. Finally, enhancing the photoresponsivity of the fabricated photodetector, post-deposition plasma treatment process was employed. A remarkable modification of the device performance was noticed as a result of plasma treatment. These modifications are representative in a decrease of series resistance and an increase of photoresponsivity and specific detectivity. The process of plasma treatment achieved an increment of external quantum efficiency from 5.53% to 8.34% at -3.5 V under UV illumination.

광선추적을 사용한 나사산 표면결함 검사용 환형 광학계 개발 (Development of Annular Optics for the Inspection of Surface Defects on Screw Threads Using Ray Tracing Simulation)

  • 이지원;임영은;박근;나승우
    • 한국정밀공학회지
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    • 제33권6호
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    • pp.491-497
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    • 2016
  • This study aims to develop a vision inspection system for screw threads. To inspect external defects in screw threads, the vision inspection system was developed using front light illumination from which bright images can be obtained. The front light system, however, requires multiple side images for inspection of the entire thread surface, which can be performed by omnidirectional optics. In this study, an omnidirectional optical system was designed to obtain annular images of screw threads using an image sensor and two reflection mirrors; one large concave mirror and one small convex mirror. Optical simulations using backward and forward ray tracing were performed to determine the dimensional parameters of the proposed optical system, so that an annular image of the screw threads could be obtained with high quality and resolution. Microscale surface defects on the screw threads could be successfully detected using the developed annular inspection system.

Algorithm for Discrimination of Brown Rice Kernels Using Machine Vision

  • C.S. Hwang;Noh, S.H.;Lee, J.W.
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.823-833
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    • 1996
  • An ultimate purpose of this study is to develop an automatic brown rice quality inspection system using image processing technique. In this study emphasis was put on developing an algorithm for discriminating the brown rice kernels depending on their external quality with a color image processing system equipped with an adaptor for magnifying the input image and optical fiber for oblique illumination. Primarily , geometrical and optical features of sample images were analyzed with unhulled paddy and various brown rice kernel samples such as sound, cracked, green-transparent , green-opaque, colored, white-opaque and brokens. Secondary, an algorithm for discrimination of the rice kernels in static state was developed on the basis of the geometrical and optical parameters screened by a statistical analysis(STEPWISE and DISCRIM Procedure, SAS ver.6). Brown rice samples could be discriminated by the algorithm developed in this study with an accuracy of 90% to 96% for the sound , cracked, colored, broken and unhulled , about 81% for the green-transparent and the white-opaque and about 75% for the green-opaque, respectively. A total computing time required for classification was about 100 seconds/1000 kernels with the PC 80486-DX2, 66MHz.

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비젼에 의한 감성인식 (Emotion Recognition by Vision System)

  • 이상윤;오재흥;주영훈;심귀보
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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    • pp.203-207
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    • 2001
  • In this Paper, we propose the neural network based emotion recognition method for intelligently recognizing the human's emotion using CCD color image. To do this, we first acquire the color image from the CCD camera, and then propose the method for recognizing the expression to be represented the structural correlation of man's feature Points(eyebrows, eye, nose, mouse) It is central technology that the Process of extract, separate and recognize correct data in the image. for representation is expressed by structural corelation of human's feature Points In the Proposed method, human's emotion is divided into four emotion (surprise, anger, happiness, sadness). Had separated complexion area using color-difference of color space by method that have separated background and human's face toughly to change such as external illumination in this paper. For this, we propose an algorithm to extract four feature Points from the face image acquired by the color CCD camera and find normalization face picture and some feature vectors from those. And then we apply back-prapagation algorithm to the secondary feature vector. Finally, we show the Practical application possibility of the proposed method.

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퍼지제어에 의한 PV시스템의 PCS 출력특성 (PCS Power Characteristics of PV System by Fuzzy Controller)

  • 문은아;임흥우;백형래;조금배;오금곤;임양수;김평호
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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    • pp.147-150
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    • 2004
  • Maximum power point tracking for PV systems traditionally uses either perturbation and observation method or incremental conductance method. Both methods require modulation of the output voltage and this leads to significant power loss. In this paper, a method, which senses output circuit voltage and short circuit current and use the above two parameters for optimum control with a fuzzy controller, is introduced. The short circuit current of PV cell represents illumination, and the output circuit voltage carry on information about the temperature. PCS(power conditioning system) is controlled not only feed to inverter for stability voltage variation despite of variety external environment, but also operate in order to feeding voltage and current at maximum power point by boost type chopper.

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칼코게나이드 유리반도체를 이용한 온도센서에 관한 연구 (A Study of Thermal Sensor Using Chalcogenide Classy Semiconductor)

  • 임석범;임동준;양준모;김영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.439-442
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    • 2001
  • Chalcogenide glassy semiconductors(CGS) can be obtained by the melt quenching technique. We have investigated the thin film heterostructures : metal-chalcogenide glassy semiconductors, where metal is copper, and chalcogenide glassy semiconductors are glasses of the system As-Se. CU/CGS film heterostructure were produced in the vacuum evaporator by the method of vacuum thermal evaporation. Doped films are very sensitive to external actions, and this property allows developing supersensitive precision sensors of temperature, humidity, illumination, and etc. based on them. Cu/CGS film has shown that resistance strongly depend on the temperature. The ratio of resistance vs. temperature has shown over a 2 k$\Omega$/degree. The slop of temperature and resistance shows linear.

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비정질 칼코게나이드 반도체를 이용한 박막온도센서 (Thin Film Thermal Sensor using Amorphous Chalcogenide Semiconductor)

  • 문형돈;임동준;김화영;소동석;이진민;조봉희;김영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.727-730
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    • 2002
  • Chalcogenide glassy semiconductors(CGS) can be obtained by the melt quenching technique. We have investigated the thin film heterostructures : metal-chalcogenide glassy semiconductors, where metal is copper, and chalcogenide glassy semiconductors are glasses of the system As-Se. Cu/CGS film heterostructure were produced in the vacuum evaporator by the method of vacuum thermal evaporation. Doped films are very sensitive to external actions, and this property allows developing supersensitive precision sensors of temperature, humidity, illumination, and etc. based on them. Cu/CGS film has shown that resistance strongly depend on the temperature. The slop of temperature and resistance shows linear.

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A New Face Detection Method by Hierarchical Color Histogram Analysis

  • Kwon, Ji-Woong;Park, Myoung-Soo;Kim, Mun-Hyuk;Park, Jin-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.138.3-138
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    • 2001
  • Because face has non-rigid structure and is influenced by illumination, we need robust face detection algorithm with the variations of external environments (orientation of lighting and face, complex background, etc.). In this paper we develop a new face detection algorithm to achieve robustness. First we transform RGB color into other color space, in which we can reduce lighting effect much. Second, hierarchical image segmentation technique is used for dividing a image into homogeneous regions. This process uses not only color information, but also spatial information. One of them is used in segmentation by histogram analysis, the other is used in segmentation by grouping. And we can select face region among the homogeneous regions by using facial features.

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