• 제목/요약/키워드: Projection function

검색결과 278건 처리시간 0.031초

Line-profile Formula in the Carbon Nanotubes by Electron Spin Resonance

  • Park, Jung-Il;Lee, Haeng-Ki
    • 한국자기공명학회논문지
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    • 제16권1호
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    • pp.11-21
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    • 2012
  • The line-width of carbon nanotubes (CNTs) was studied as a function of the temperature at a frequency of 9.49 GHz in the presence of external electromagnetic radiation. The relative frequency dependence of the absorption power is obtained with the projection operator technique (POT) proposed by Kawabata. The line-width increased as the temperature increased in the high-temperature region (T>200 K). The scattering is little affected in the low-temperature region (T<200 K) because there is no correlation between the resonance field and the Fermi-Dirac distribution function. Thus, the present technique is considered to be more convenient to explain the resonant system as in the case of other optical transition problems.

Harris Corner Detection for Eyes Detection in Facial Images

  • Navastara, Dini Adni;Koo, Kyung-Mo;Park, Hyun-Jun;Cha, Eui-Young
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 춘계학술대회
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    • pp.373-376
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    • 2013
  • Nowadays, eyes detection is required and considered as the most important step in several applications, such as eye tracking, face identification and recognition, facial expression analysis and iris detection. This paper presents the eyes detection in facial images using Harris corner detection. Firstly, Haar-like features for face detection is used to detect a face region in an image. To separate the region of the eyes from a whole face region, the projection function is applied in this paper. At the last step, Harris corner detection is used to detect the eyes location. In experimental results, the eyes location on both grayscale and color facial images were detected accurately and effectively.

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시선추적을 위한 실시간 동공 중심 검출 (Real-time pupil center detection for gaze tracking)

  • 이경주;김계영
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2014년도 제49차 동계학술대회논문집 22권1호
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    • pp.59-61
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    • 2014
  • 본 논문에서는 단일의 카메라로부터 획득한 영상에 있는 동공 중심을 실시간으로 검출하는 알고리즘을 제안한다. 제안하는 방법은 원에서 현의 수직이등분선은 그 원의 중심을 지난다는 사실을 이용하여 동공의 현을 찾고 동공 중심을 계산하는 것이다. 먼저 VPF(Variance Projection Function)을 이용해 일차적으로 동공 중심을 탐지한다. 탐지된 중심점을 기준으로 원을 탐색하여 정확한 동공 중심점을 찾는다. 실험을 통하여 제안한 방법은 높은 검출율과 처리시간 관점에서 우수함을 보인다.

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SOME GEOMETRIC PROPERTIES OF GOTZMANN COEFFICIENTS

  • Jeaman Ahn
    • 충청수학회지
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    • 제37권2호
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    • pp.57-66
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    • 2024
  • In this paper, we study how the Hilbert polynomial, associated with a reduced closed subscheme X of codimension 2 in ℙN, reveals geometric information about X. Although it is known that the Hilbert polynomial can tell us about the scheme's degree and arithmetic genus, we find additional geometric information it can provide for smooth varieties of codimension 2. To do this, we introduce the concept of Gotzmann coefficients, which helps to extract more information from the Hilbert polynomial. These coefficients are based on the binomial expansion of values of the Hilbert function. Our method involves combining techniques from initial ideals and partial elimination ideals in a novel way. We show how these coefficients can determine the degree of certain geometric features, such as the singular locus appearing in a generic projection, for smooth varieties of codimension 2.

휴대용 열 영상 관측 장비를 위한 전자적 영상 안정화 (Electronic Image Stabilization for Portable Thermal Image Camera)

  • 김종호
    • 한국군사과학기술학회지
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    • 제19권3호
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    • pp.288-293
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    • 2016
  • Electronic Image Stabilization(EIS) is widely used as a technique for correcting a shake of an image. The case requiring the EIS function has been increased in high magnification thermal image observation on portable military equipment. Projection Algorithm(PA) for EIS is easy to implement but its performance is sensitive to the projection area. Especially, projection profiles of thermal image have very modest change and are difficult to extract image shifts between frames. In this paper, we proposed algorithm to extract a feature image for the thermal image and compared Block Matching Algorithm(BMA) with PA using our proposed feature image. When using our proposed feature image, BMA was simply implemented using FPGA's internal small memory. And we were able to obtain 30 % PSNR improved results compared to PA.

Strong Convergence of a Bregman Projection Method for the Solution of Pseudomonotone Equilibrium Problems in Banach Spaces

  • Olawale Kazeem Oyewole;Lateef Olakunle Jolaoso;Kazeem Olalekan Aremu
    • Kyungpook Mathematical Journal
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    • 제64권1호
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    • pp.69-94
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    • 2024
  • In this paper, we introduce an inertial self-adaptive projection method using Bregman distance techniques for solving pseudomonotone equilibrium problems in reflexive Banach spaces. The algorithm requires only one projection onto the feasible set without any Lipschitz-like condition on the bifunction. Using this method, a strong convergence theorem is proved under some mild conditions. Furthermore, we include numerical experiments to illustrate the behaviour of the new algorithm with respect to the Bregman function and other algorithms in the literature.

저조사광 재구성을 위한 필터 설계 (Modifcation of Reconstruction Filter for Low-Dose Reconstruction)

  • 염영호
    • 대한전자공학회논문지
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    • 제17권1호
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    • pp.23-30
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    • 1980
  • C.T.(전산화 단층 영상 처리) 영상재구성의 경우, 투사되는 광양자(X-ray, positron 등)가 적을 때는 잡음에 의한 효과가 증폭되어 재구성된 화면은 거의 알아 볼 수 없게 된다. 그 경우 화질을 높이깅 nl해서는 재구성 필터를 사영 데이터(projection data)의 신호대잡음비에 따라 수정시켜야 할 필요성이 생긴다. 이 논문에서는 사영 데이터에서 얻은 정보를 사용하여 재구성 필터를 수정하는 방법에 관하여 고찰하고 그에 대한 시뮬레이션을 행하였다. 시뮬레이션의 결과, 이 방법은 재구성 화상에서의 잡음을 줄여, 그 분해능력을 크게 향상시킬 수 있음이 판명되었다. 또한 이 필터를 근사적으로 구현하는 방법에 관하여도 논하고, 그 근사 필터의 회귀적 구성(recursive implementation)의 가능성에 관하여도 언급하였다.

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Recognition of English Calling Cards by Using Projection Method and Enhanced RBE Network

  • Kim, Kwang-Baek
    • 한국지능시스템학회논문지
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    • 제13권4호
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    • pp.474-479
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    • 2003
  • In this paper, we proposed the novel method for the recognition of English calling cards by using the projection method and the enhanced RBF (Radial Basis Function) network. The recognition of calling cards consists of the extraction phase of character areas and the recognition phase of extracted characters. In the extraction phase, first of all, noises are removed from the images of calling cards, and the feature areas including character strings are separated from the calling card images by using the horizontal smearing method and the 8-directional contour tracking method. And using the image projection method, the feature areas are split into the areas of individual characters. We also proposed the enhanced RBF network that organizes the middle layer effectively by using the enhanced ART1 neural network adjusting the vigilance threshold dynamically according to the homogeneity between patterns. In the recognition phase, the proposed neural network is applied to recognize individual characters. Our experiment result showed that the proposed recognition algorithm has higher success rate of recognition and faster learning time than the existing neural network based recognition.

스퀸트 모드 SAR 영상 형성을 위한 역투영 알고리즘에서의 자동초점 기법 적용 연구 (A Study on Autofocus Method for Back-Projection Algorithm under the Squint Mode in Synthetic Aperture Radar)

  • 황정훈;김환우
    • 전자공학회논문지
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    • 제54권7호
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    • pp.81-89
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    • 2017
  • 요동이 존재하는 환경에서, 요동 측정 오차에 의한 성능 저하를 극복하기 위한 신호처리 방식의 자동초점(Autofocus, AF) 기법의 적용은 필수적이다. 본 논문에서는 스퀸트 모드에서 획득한 합성 개구면 레이다 데이터에 역투영 알고리즘(back-projection algorithm, BPA)으로 영상을 형성하고, AF를 효과적으로 적용하기 위한 방식을 연구하였다. 자동 초점 기법의 효과적인 적용을 위해 BPA 영상을 회전한 상태로 형성하는 방식을 제안하며, 이때 필요한 후처리 도플러 위치 정렬 함수를 유도하였으며, 비행시험을 통해 획득한 SAR(Synthetic Aperture Radar, SAR) 원시 데이터에 적용하여 성능 개선을 확인함으로써, 실 데이터에서도 유효한 방식임을 확인하였다.