• Title/Summary/Keyword: Adaptive Contrast

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Self-Recurrent Wavelet Neural Network Based Terminal Sliding Mode Control of Nonlinear Systems with Uncertainties (불확실성을 갖는 비선형 시스템의 자기 회귀 웨이블릿 신경망 기반 터미널 슬라이딩 모드 제어)

  • Lee, Sin-Ho;Choi, Yoon-Ho;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.315-317
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    • 2006
  • In this paper, we design a terminal sliding mode controller based on neural network for nonlinear systems with uncertainties. Terminal sliding mode control (TSMC) method can drive the tracking errors to zero within finite time. Also, TSMC has the advantages such as improved performance, robustness, reliability and precision by contrast with classical sliding mode control. For the control of nonlinear system with uncertainties, we employ the self-recurrent wavelet neural network(SRWNN) which is used for the prediction of uncertainties. The weights of SRWNN are trained by adaptive laws based on Lyapunov stability theorem. Finally, we carry out simulations to illustrate the effectiveness of the proposed control.

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New Algorithm for Recursive Estimation in Linear Discrete-Time Systems with Unknown Parameters

  • Shin Vladimir;Ahn Jun-Il;Kim Du-Yong
    • International Journal of Control, Automation, and Systems
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    • v.4 no.4
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    • pp.456-465
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    • 2006
  • The problem of recursive filtering far linear discrete-time systems with uncertainties is considered. A new suboptimal filtering algorithm is herein proposed. It is based on the fusion formula, which represents an optimal mean-square linear combination of local Kalman estimates with weights depending on cross-covariances between local filtering errors. In contrast to the optimal weights, the suboptimal weights do not depend on current measurements, and thus the proposed algorithm can easily be implemented in real-time. High accuracy and efficiency of the suboptimal filtering algorithm are demonstrated on the following examples: damper harmonic oscillator motion and vehicle motion constrained to a plane.

Psychodynamic Psychotherapy of PTSD (외상 후 스트레스 장애의 역동정신치료)

  • Kim, Jung-Young;Park, Jong-Il;Yang, Jong-Chul
    • Anxiety and mood
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    • v.11 no.2
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    • pp.106-113
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    • 2015
  • In psychodynamic therapy, trauma related symptoms are considered as an attempt to overcome the traumatic experiences. Therefore, psychodynamic psychotherapy regards the symptom not as a patient's defect but as an adaptive reaction. In contrast to other therapies, psychodynamic theory places heavy emphasis on the understanding and resolution of the patient's symptoms. In addition, transference is a distinctive feature of this theory, which plays a significant role of reflecting the realistic evaluation on the therapist's characteristics, and in guaranteeing the therapeutic alliance. The psychodynamic therapist inducts meaning from the patient's unconscious mind. The therapist's task is to help the patient to better understand defense mechanisms guide their management of experiences and reactions, and facilitate a better understanding of their personal experiences.

An Adaptive Image Quality Assessment Algorithm

  • Sankar, Ravi;Ivkovic, Goran
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.6-13
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    • 2012
  • An improved algorithm for image quality assessment is presented. First a simple model of human visual system, consisting of a nonlinear function and a 2-D filter, processes the input images. This filter has one user-defined parameter, whose value depends on the reference image. This way the algorithm can adapt to different scenarios. In the next step the average value of locally computed correlation coefficients between the two processed images is found. This criterion is closely related to the way in which human observer assesses image quality. Finally, image quality measure is computed as the average value of locally computed correlation coefficients, adjusted by the average correlation coefficient between the reference and error images. By this approach the proposed measure differentiates between the random and signal dependant distortions, which have different effects on human observer. Performance of the proposed quality measure is illustrated by examples involving images with different types of degradation.

Human Visual System Based Adaptive Watermarking in Frequency Domain (HVS 기반 주파수 공간에서의 적응적인 워터마킹)

  • Park, Ki-Hong;Yoon, Byung-Min;Kim, Yoon-Ho
    • Journal of Advanced Navigation Technology
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    • v.9 no.2
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    • pp.170-176
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    • 2005
  • In this paper, we proposed watermarking algorithm based on wavelet transform. Discrete wavelet transform is involved to calculate additive energy strength. Considering imperceptibility, after computing contrast and texture sensitivity in gray-level image, we inserted watermark with variable weight due to the feature of coefficient block. Consequently, applying human visual system, the experimental results showed that the proposed algorithm satisfied the properties of robustness and imperceptibility that are the major conditions of watermarking.

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Visually-Adaptive Quantization method Based on Block DCT (DCT 기반 영상의 시각 적응적 양자화 방법에 관한 연구)

  • 김정현;박성찬;천승환;이귀상
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.04b
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    • pp.604-606
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    • 2000
  • 본 논문에서는 인간의 시각 특성을 고려한 시각 적응적 DCT 영상 압축 방법이 제안되었다. 인간의 시각 체계의 특성 중 복잡한 영사이나 대비효과(contrast)가 큰 부분에서는 압축과정에서 발생한 왜곡이 쉽게 눈에 인지되지 않는 특성을 갖는 공간적 마스킹(spatial masking)을 이용하여 영상의 질을 어느정도 유지하면서 적응적 압축 방법에 의해 압축율을 보다 높이는 방법을 제시하였다. DCT 변환 블록에서 경계영역 정보를 많이 포함하는 부분을 추출한 후 이 영역은 다른 영역에 비해 복잡도가 더 높고 경계성분의 대비효과가 더 크기 때문에 이 영역의 분산을 취해 이 값에 따라 적응적으로 양자화한다. 실험결과, 제안된 영상 압축 알고리즘은 기존의 시각 적응적 압축 방법보다 좋은 성능을 보이며 특히 고주파 성분을 많이 가진 복잡한 영상에 대하여 높은 압축률을 보였다.

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Contrast-enhanced volume visualization of tumor based on adaptive opacity transfer function (적응적 투명도 전이함수기반 종양영역 대조도강화 볼륨가시화)

  • Song Soo-Min;Lee Joung-Min;Kim Kyeong-Min;Kim Myoung-Hee
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06a
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    • pp.127-129
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    • 2006
  • 본 논문은 종양을 주입한 쥐의 FDG-PET영상에서 정상세포보다 포도당대사가 활발한 종양조직의 3차원적 위치를 파악하고 잔여암 전이여부를 판별하기 위한 3차원 볼륨 가시화기법을 제안한다. 종양조직과 주변조직의 시각적 대비를 크게 하기 위해 명암도 분포에 따라 조직을 여러 클러스터로 나눈 후, 적응적 투명도 전이함수를 사용하였다. 관심영역을 불투명하게 표현하고 조직간 투명도 변화량을 크게 줌으로써 잡음이 심한 PET 영상에서 전경영역과 배경영역을 구분할 수 있었고, 명확한 시각대비 결과를 얻을 수 있었다. 추후 명암도값 외에 영암도 기울기, 관심영역 우선순위 등을 고려한 다차원 전이함수기법으로 확장함으로써 종양영역의 경계를 더욱 강조할 수 있을 것으로 기대된다.

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Extraction and Shape Description of Feature Region on Ocular Fundus Fluorescein Angiogram (형광 안저화상에 관한 특수 영역의 유출 및 모양)

  • Go, Chang-Rim;Ha, Yeong-Ho;Kim, Su-Jung
    • Journal of Biomedical Engineering Research
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    • v.8 no.1
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    • pp.81-86
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    • 1987
  • An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.

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Adaptive Watermarking based on Fuzzy Inference and Human Visual System (퍼지 추론과 시각특성 기반의 적응적 워터마킹)

  • Shin Hee-Jong;Park Ki-Hong;Kim Yoon-Ho
    • Journal of Digital Contents Society
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    • v.5 no.4
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    • pp.311-315
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    • 2004
  • In this paper, we proposed a robust watermarking algorithm based on fuzzy inference and human visual system. In the first, discrete wavelet transform(DWT) is involved to calculate additive energy strength, then we devised fuzzy inference, which was established by computing contrast and texture degree in gray-level image. Watermark is embeded into the coefficients of 3-level DWT so as to consider a spatial effects. Visual recognizable patterns such as binary image were used as a watermark Consequently, experimental results showed that proposed algorithm is robust in JPEC compression.

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Moving Object Detection and Tracking in Moving Picture Using Adaptive Thresholding (동영상에서의 적응적인 임계화를 통한 움직임 검출 및 추적)

  • 정미영;최석림
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.17-20
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    • 2002
  • The methods that track and detect motion field based on image difference of successive images from camera can separate motion field and background effectively, but because of noise and background images getting proper difference images is hard to achieve. In this paper we propose a method that can improve difference image quality significantly. Three step process is used. At the first step, existence of motion field is determined, the second step is finding proper threshold value using 'Contrast Streching' technique which enables us to find proper motion field even in complex images. At last step, remaining noise is removed and motion field is determined.

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