• Title/Summary/Keyword: Noise robustness

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A ROBUST WATERMARKING METHOD BASED ON HVS (HVS 기반 워터마킹에서 외부 공격에 강인한 방법에 관한 연구)

  • 심상흔;정용주;강호경;노용만
    • Proceedings of the IEEK Conference
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    • 2001.06d
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    • pp.73-76
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    • 2001
  • In this paper, we utilize a HVS(Human Visual System) watermarking method where watermarks are embedded in a DFT domain. The HVS watermarking method is robust for attacks like JPEC, filtering, noise, etc. But, when images are attacked by basic geometric attacks as cropping, scaling, rotation, a watermarks may not be detected. In this paper, we introduce the HVS watermarking method that inserts references In a domain of LSB(Least Significant Bit) of image. Experimental results show that the proposed method based on HVS watermarking method gives more robustness to the basic geometric attacks compared with original HVS watermarking methods.

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WATERMARKING OF DIGITAL IMAGES BASED ON PRINCIPAL COMPONENT ANALYSIS

  • Thai, Hien-Duy;Zensho Nakao;Chen, Yen-Wei
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.484-487
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    • 2003
  • A new domain PCA-based approach to watermarking is presented. This method is applied to digital images to embed and detect a watermark. The performance of PCA approach is compared to traditional frequency domain watermark models. Simulation shows the performance of the proposed method with excellent result against image cropping and robustness against some attacks such as additive noise, filtering and jpeg compression.

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Improved Blind Multipath Estimation for Long Code DS-CDMA

  • Yu Qian;Bi Guoan;Zhang Gaonan
    • Journal of Communications and Networks
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    • v.7 no.3
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    • pp.278-283
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    • 2005
  • This paper proposes a blind channel estimation scheme for long code direct sequence code division multiple access (DS­CDMA) systems with multipath fading channels. This scheme combines the advantages of Toeplitz displacement and correlation matching methods to achieve improved performance. The basic idea is to remove the effects of noise and interferences with Toeplitz displacement operation and then estimate the multi path channel parameters with the correlation matching method. Simulation results are presented to show that the proposed scheme provides better MSE performance and robustness against the near-far problem.

Development of Sound Source Localization System using Explicit Adaptive Time Delay Estimation

  • Kim, Doh-Hyoung;Park, Youngjin
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.80.2-80
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    • 2002
  • The problem of sound source localization is to determine the position of sound sources using the measurement of the acoustic signals received by microphones. To develop a good sound source localization system which is applicable to a mobile platform such as robots, a time delay estimator with low computational complexity and robustness to background noise or reverberations is necessary. In this paper, an explicit adaptive time delay estimation method for a sound source localization system is proposed. Proposed explicit adaptive time estimation algorithm employs direct adaptation of the delay parameter using a transform-based optimization technique, rather than...

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Robust adaptive control for a stable nonminimum phase system (안정한 비최소 위상 시스템의 견실한 적응제어)

  • 최종호;김호찬
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.255-260
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    • 1988
  • A robust adaptive control method for a stable nonminimum phase SISO system with unmodelled dynamics is proposed. The robust parameter estimation method of the system with bounded output noise and unmodelled dynamics is employed and a parallel structure is proposed to improve the robustness of adaptive control system. The local stability of the proposed system is shown. Computer simulations are done in order to compare the performance of the proposed structure with the basic structure on various circumstance.

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Tire tread pattern classification using gray level cooccurrence matrix for the binary image (이치화 영상에 대한 계조치 동시발생행렬을 이용한 타이어 접지 패턴의 분류)

  • 박귀태;김민기;김진헌;정순원
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.100-105
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    • 1992
  • Texture is one of the important characteristics that has been used to identify objects or regions of interest in an image. Tire tread patterns can be considered as a kind of texture, and these are classified with a texture analysis method. In this sense, this paper proposes a new algorithm for the classification of tire tread pattern. For the classification, cooccurrence matrix for the binary image is used. The performances are tested by experimentally 8 different tire tread pattern and the robustness is examined by including some kinds on noise.

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Robust servomechanism problem for linear discrete systems (선형 이산치 시스템의 Robust Servomechanism 문제)

  • ;Na, Seung You
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.135-138
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    • 1987
  • A method for designing a robust tracking controller for linear discrete systems is investigated. Only the observable variables are to be used in the controller synthesis. To insure the robustness, the system is augmented by a compensator at the output side. Then a feedback controller is designed using delayed values of the observable variables for the augmented system. The delay times are chosen to minimize the effect of measurement accuracy and/or noise.

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A Study on Endpoint Detection and Syllable Segmentation System Using Ramp Edge Detection (Ramp Edge Detection을 이용한 끝점 검출과 음절 분할에 관한 연구)

  • 유일수;홍광석
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2216-2219
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    • 2003
  • Accurate speech region detection and automatic syllable segmentation is important part of speech recognition system. In automatic speech recognition system, they are needed for the purpose of accurate recognition and less computational complexity, In this paper, we Propose improved syllable segmentation method using ramp edge detection method and residual signal Peak energy. These methods were used to ensure accuracy and robustness for endpoint detection and syllable segmentation system. They have almost invariant response to various background noise levels. As experimental results, we obtained the rate of 90.7% accuracy in syllable segmentation in a condition of accurate endpoint detection environments.

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A SYMMETRIC-DEFINITE PENCIL APPROACH TO SOURCE SEPARATION

  • Park, Seungjin
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1827-1830
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    • 2002
  • A matrix pencil method for source separation 〔3〕was shown to be an unbiased signal extractor in the presence of temporally white noise. Its efficiency and robustness lies in the fact that the method in 〔3〕 employs only time-delayed correlation matrices of the observation data, In this paper we stress out that the matrix pencil method might suffer from a numerical instability problem, be- cause the symmetric-definite pencil was not exploited. Moreover we present a simple method of constructing a symmetric-definite pencil so that the matrix pencil method is numerically stable.

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An Improved Histogram-Based Image Hash (Histogram에 기반한 Image Hash 개선)

  • Kim, So-Young;Kim, Hyoung-Joong
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.531-534
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    • 2008
  • Image Hash specifies as a descriptor that can be used to measure similarity in images. Among all image Hash methods, histogram based image Hash has robustness to common noise-like operation and various geometric except histogram _equalization. In this_paper an improved histogram based Image Hash that is using "Imadjust" filter I together is proposed. This paper has achieved a satisfactory performance level on histogram equalization as well as geometric deformation.

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