• Title/Summary/Keyword: Adaptive Contrast

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Recursive Estimation of Biased Zero-Error Probability for Adaptive Systems under Non-Gaussian Noise (비-가우시안 잡음하의 적응 시스템을 위한 바이어스된 영-오차확률의 반복적 추정법)

  • Kim, Namyong
    • Journal of Internet Computing and Services
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    • v.17 no.1
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    • pp.1-6
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    • 2016
  • The biased zero-error probability and its related algorithms require heavy computational burden related with some summation operations at each iteration time. In this paper, a recursive approach to the biased zero-error probability and related algorithms are proposed, and compared in the simulation environment of shallow water communication channels with ambient noise of biased Gaussian and impulsive noise. The proposed recursive method has significantly reduced computational burden regardless of sample size, contrast to the original MBZEP algorithm with computational complexity proportional to sample size. With this computational efficiency the proposed algorithm, compared with the block-processing method, shows the equivalent robustness to multipath fading, biased Gaussian and impulsive noise.

A Critical Review of Current Crisis Simulation Methodology

  • Kim, Hak-Kyong;Lee, Ju-Lak
    • International Journal of Contents
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    • v.7 no.1
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    • pp.58-64
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    • 2011
  • This paper is concerned with simulation exercises used to train key response agencies for crisis situations. While 'multi-agency' simulations are increasingly acknowledged as a necessary and significant training tool for emergency response organisations, many current crisis simulations are still focused on the revision of existing response plans only. However, a crisis requires a rapid reaction, yet in contrast to an 'emergency', the risks for critical decision makers in crisis situations are difficult to measure, owing to their ill-structure. In other words, a crisis situation is likely to create great uncertainty, unfamiliarity and complexity, and consequently should be managed by adaptive or second order expertise and techniques, rather than routine or structured responses. In this context, the paper attempts to prove that the current practices of simulation exercises might not be good enough for uncertain, unfamiliar, and complex 'crisis' situations, in particular, by conducting case studies of two different underground fire crises in Korea (Daegu Subway Fire 2003) and the UK (King's Cross Fire 1987). Finally, it is suggested that the three abilities: 'flexibility', 'improvisation' and 'creativity' are critical in responding to a crisis situation.

Caption Region Extraction of Sports Video Using Multiple Frame Merge (다중 프레임 병합을 이용한 스포츠 비디오 자막 영역 추출)

  • 강오형;황대훈;이양원
    • Journal of Korea Multimedia Society
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    • v.7 no.4
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    • pp.467-473
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    • 2004
  • Caption in video plays an important role that delivers video content. Existing caption region extraction methods are difficult to extract caption region from background because they are sensitive to noise. This paper proposes the method to extract caption region in sports video using multiple frame merge and MBR(Minimum Bounding Rectangles). As preprocessing, adaptive threshold can be extracted using contrast stretching and Othu Method. Caption frame interval is extracted by multiple frame merge and caption region is efficiently extracted by median filtering, morphological dilation, region labeling, candidate character region filtering, and MBR extraction.

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Improved transient response design of MRACS

  • Oki, toshitaka;Shin, Seungin;Tanaka, Kanya;Shimizu, Akira;Shibata, Satoru
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.488-493
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    • 1994
  • The global stability of model reference adaptive control system (MRACS) in the ideal case was resolved in the 1980's. Hoever the improvement of the transient, behaviour of MRACS has not been discussed sufficiently even in the ideal case. Only a few attempts have so far been made at the application of MRACS to the practical systems in contrast to the theoretical systematization. Therefore, when we consider the practical usage of MRACS it is necessary to develop an improved design scheme with respect to transient behaviour. In this paper, we propose two design schemes improving transient behaviour of MRACS by mollifying the input synthesis in the conventional design scheme of MRACS. We present a design scheme of MRACS in which we utilize the design approach of variable structure system(VSS). After describing the above design scheme, we also propose the improved design scheme in which we introduce the dead-zone decided by the magnitude of the output-error between the plant and the reference model. The effectiveness of the proposed two design schemes are shown through computer simulations. As the results, by using these methods, the convergence of the transient response is greatly improved in comparison with the conventional one.

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자력복구 적응 채널등화기를 위한 Run and Go 알고리즘 (Run and Go Algorithm for Blind Equalization)

  • Chung, Won-Zoo
    • Journal of IKEEE
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    • v.10 no.1 s.18
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    • pp.62-68
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    • 2006
  • In this paper, we propose an adaptation strategy for blind equalizers, which combines a blind algorithm based on high order statistics and the decision directed LMS algorithm. In contrast to 'Stop-and-Go' algorithm, where adaptation is stopped for unreliable signals, the proposed algorithm applies high order statistics (HOS) blind algorithm to the unreliable signals and applies DD-LMS for the reliable signals. The proposed algorithm, named 'Run-and-Go' algorithm, inherits minimum MSE performance of DD-LMS and acquisition ability of blind algorithms. Furthermore, by updating the reliable signal region according to signal quality in each iteration, the convergence speed and acquisition ability is further improved.

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A Study about Modeling and Control of Dynamic Absorber for Vehicle by Using Active Viscous Damping (능동적 점성감쇠를 이용한 차량용 동적 흡진기의 모델링과 제어에 관한 연구)

  • 김대원;배준영
    • Journal of KSNVE
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    • v.9 no.1
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    • pp.121-130
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    • 1999
  • Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

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A Contrast Enhancement algorithm using adaptive threshold in infrared image environment (적외선 영상 환경에서 적응형 임계값을 이용한 동적영역 분할 히스토그램 평활화 기법)

  • Oh, Sun-Mi;Song, Joongseok;Park, Jong-Il
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.11a
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    • pp.150-153
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    • 2014
  • 영상 표시 장치에서 대조 이미지의 왜곡 현상을 보완하기 위해 히스토그램 평활화(Histogram Equalization)와 플래토 평활화(Plateau Equalization)가 사용된다. 히스토그램 평활화(Histogram Equalization)를 이용하여 명암대비를 증가 시킬 경우 과도한 이미지의 밝기 변화에 따른 과포화 현상이 발생하며 실시간 시스템에서는 물체 추적에 왜곡 현상이 발생한다. 특히, 적외선 영상(infrared image)과 같이 명암비가 한쪽으로 치우쳐 있는 영상들을 명암비를 개선하기 위해서는 플래토 평활화(Plateau Equalization)와 같은 영상 개선 방법이 필수적이다. 플래토 평활화에서는 임계값을 사용하는 방법이 제시되고 있지만 실험에 의한 최적 임계값을 찾아내는 방식이며, 이 방법은 입력되는 새로운 영상마다 임계값을 실험에 의해 매번 반복해서 도출해야 문제점이 있다. 본 논문에서 제안하는 방법은 과포화 되는 이미지 영역의 문제를 해결하기 위해 제시하는 방법으로 히스토그램 평활화(Histogram Equalization)의 동적 분할하는 알고리즘에 근거하되, 입력 영상에따라 적응적으로 임계값을 설정하는 기법을 제안한다. 실험을 통해 제안하는 방법이 실시간 영상에서 기존의 동적분할 히스토그램에 비해 자연스럽게 명암비를 개선하여 과포화 되거나 중요한 정보를 누락하여 왜곡 되지 않게 자연스러운 화면을 재생하는 방법을 제안한다.

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Detection of TFT-LCD Defects Using Independent Component Analysis (독립성분분석을 이용한 TFT-LCD불량의 검출)

  • Park, No-Kap;Lee, Won-Hee;Yoo, Suk-In
    • Journal of KIISE:Software and Applications
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    • v.34 no.5
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    • pp.447-454
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    • 2007
  • TFT-LCD(Thin Film transistor liquid crystal display) has become actively used front panel display technology with increasing market. Intrinsically there is region of non uniformity with low contrast that to human eye is perceived as defect. As the gray level difference between the defect and the background is hardly distinguishable, conventional thresholding and edge detection techniques cannot be applied to detect the defect. Between the patterned and un-patterned LCD defects, this paper deals with un-patterned LCD defects by using independent component analysis, adaptive thresholding and skewness. Our method showed strong results even on noised LCD images and worked successfully on the manufacturing line.

A Development of a Medical Information Transmisson System in Moving Picture Form(MedMpeg)

  • Choi, Jong U.;Cho, Hune
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.2 no.1
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    • pp.131-139
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    • 1998
  • With the rapid development of communication technology and widespread uses of internet service, utilization of internet-based medical information systems which transmitts moving pictures of medical objects is becoming a common practice. The internet-based medical information service prvovides richer information than conventional services such as touch-tone telephone, personal computers e-mails, or pagers, because "a picture is worth a thousand words". However, the systems passively transmits moving pictures of the medical objects to the users, and thus the system cannot intelligently adjust itself to provide better service. As the tradeoff exists between transmission speed and quality of the image, there is a need that moving pictures be analyzed to adjust the trnasmission speed and image quality. When very little difference between consecutive images are detected, the system can automatically increase the size of the image files, thus enhancing the quality of image. In contrast, the system should increase the number of images to send more pictorial information by sacrificing the quality of each individual image, when a significant difference is detected. In this paper an adaptive filtering technique is introduced which adjusts the quality of image and transmission speed according to a clinical situation in hospital.

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Effects of Allicin on Cytokine Production Genes of Human Peripheral Blood Mononuclear Cells (마늘의 Allicin이 사람 단핵세포의 사이토카인 생산 유전자의 발현에 미치는 영향)

  • 박란숙
    • The Korean Journal of Food And Nutrition
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    • v.15 no.3
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    • pp.191-196
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    • 2002
  • The effect of allicin, the major component of garlic (Allium sativum), on the gene expression profiles of peripheral blood mononuclear cells from healthy donors was analyzed. DNA microarray which can detect expression signal of 862 genes revealed that allicin induced the expression of cytokine, chemokine, and immune-related genes in peripheral blood mononuclear cells. In contrast, allicin repressed the expression of adaptive immune-related genes, which are expressed in T helper 1 Iymphocytes. Simultaneous inhibitory and stimulatory effects of allicin were found on inflammatory cells. It is likely that allicin down-regulated the expression of specific genes that were previously up-regulated in resting cells, suggesting a new mechanism by which they exert positive and negative effect. Considering the broad and renewed interest in allicin, the profiles we describe here will be useful in designing more specific and efficient treatment strategies.