• Title/Summary/Keyword: Noise robustness

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Automated Inspection System Using Image Processing Technology for Automotive Components (영상처리 기법을 이용한 자동차부품의 자동검사시스템 개발)

  • Park, Jung-Kee;Jung, Won
    • Journal of Korea Society of Industrial Information Systems
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    • v.4 no.3
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    • pp.71-78
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    • 1999
  • This paper presents an integrated and automated inspection system using image processing technology for the automotive engine assembly process. The system make it possible for the inspected data to be entered directly from the machine vision into the statistical process control system. Such direct entry enables the prompt preparation of corrective actions against process problems. An IVP-150 machine vision board is installed within the PC for image processing, and a template matching technology is implemented to precisely verify quality factors. The developed system showed robustness to the problems of noise, distortion, and orientation.

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Moving Object Segmentation Using Object Area Tracking Algorithm (움직임 영역 추출 알고리즘을 이용한 자동 움직임 물체 분할)

  • Lee Kwang-Ho;Lee Seung-Ik
    • Journal of Korea Multimedia Society
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    • v.7 no.9
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    • pp.1240-1245
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    • 2004
  • This paper presents the moving objects segmentation algorithms from the sequence images in the stationary backgrounds such as surveillance camera and video phone and so on. In this paper, the moving object area is extracted with proposed object searching algorithm and then moving object is segmented within the moving object area. Also the proposed algorithms have the robustness against noise problems and results show the proposed algorithm is able to efficiently segment and track the moving object area.

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Two-wheeler Detection using the Local Uniform Projection Vector based on Curvature Feature (이진 단일 패턴과 곡률의 투영벡터를 이용한 이륜차 검출)

  • Lee, Yeunghak;Kim, Taesun;Shim, Jaechang
    • Journal of Korea Multimedia Society
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    • v.18 no.11
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    • pp.1302-1312
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    • 2015
  • Recent research has been devoted and focused on detecting pedestrian and vehicle in intelligent vehicles except for the vulnerable road user(VRUS). In this paper suggest a new projection method which has robustness for rotation invariant and reducing dimensionality for each cell from original image to detect two-wheeler. We applied new weighting values which are calculated by maximum curvature containing very important object shape features and uniform local binary pattern to remove the noise. This paper considered the Adaboost algorithm to make a strong classification from weak classification. Experiment results show that the new approach gives higher detection accuracy than of the conventional method.

Performance Analysis of Adaptive Array Antenna for GPS Anti-Jamming (GPS 항재밍을 위한 적응 배열 안테나의 성능 분석)

  • Jeong, Taehee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.3
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    • pp.382-389
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    • 2013
  • In anti-jamming GPS receiver, adaptive signal processing techniques in which the radiation pattern of adaptive array antenna of elements may be adaptively changed used to reject interference, clutter, and jamming signals. In this paper, I describes adaptive signal processing technique using the sample matrix inversion(SMI) algorithm. This adaptive signal processing technique can be applied effectively to wideband/narrowband anti-jamming GPS receiver because it does not consider the satellite signal directions and GPS signal power level exists below the thermal noise. I also analyzed the effects of covariance matrix sample size and diagonal loading technique on the system performance of five-element circular array antenna. To attain near optimum performance, more samples required for calculation covariance matrix. Diagonal loading technique reduces the system nulling capability against low-power jamming signals, but this technique improves robustness of adaptive array antenna.

A Simple Method for Identifying Mechanical Parameters Based on Integral Calculation

  • Han, Sang-Heon;Yoo, Anno;Yoon, Sang Won;Yoon, Young-Doo
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1387-1395
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    • 2016
  • A method for the identification of mechanical parameters based on integral calculation is presented. Both the moment of inertia and the friction constant are identified by the method developed here, which is based on well-known mechanical differential equations. The mechanical system under test is excited according to a pre-determined low-frequency sinusoidal motion, minimizing the distortion, and increasing the accuracy of the results. The parameters are identified using integral calculation, increasing the robustness of the results against measurement noise. Experimental data are supported by simulation, confirming the effectiveness of the proposed technique. The performance improvements shown here are of use in the design of speed and position controllers and observers. Owing to its simplicity, this method can be readily applied to commercial inverter products.

Output Feedback LQ control of a Space Robot in Discrete-Time (우주로봇의 이산시간 출력 귀환 LQ 제어)

  • 임승철
    • Journal of KSNVE
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    • v.6 no.5
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    • pp.567-574
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    • 1996
  • This paper concerns an articulated space robot with flexible links. The equations of its motion are derived by means of the Lagrangian mechanics. Assuming that magnitude of elastic motions are relatively small, the perturbation approach is taken to separate the original equations of motion into linear and nonlinear equations. Th effect the desired payload motion, open loop control inputs are first determined based on the nonlinear equations. One the other hand, in order to reduce the positional errors during the maneuver, vibration suppression is actively done with a feedforward control for disturbance cancellation to some extent. Additionally, for performance robustness against residual disturbance, an LQ control modified to have a prescribed degree of stability is applied based on the linear equations. Measurement equations are formulated to be used for the maximum likelihood estimator to reconstruct states from the original robot equations of motion. Finally, numerical simulations show effectiveness of the proposed control design scheme.

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Vibration Control of Flexible SCARA Robots (유연한 수평 다관절 로봇의 진동제어)

  • 임승철;용대중
    • Journal of KSNVE
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    • v.7 no.3
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    • pp.387-392
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    • 1997
  • This paper concerns a SCARA robot with the flexible forearm linked to the rigid upper arm. The equations of motion are derived by the Lagrangian mechanics. For controller design, the perturbation approach is taken to separate the original equations of motion into linear equations describing small perturbed motions and nonlinear equations describing purely rigid motion of the robot. To effect the desired payload motion, open loop control inputs are determined based on the inverse dynamics of the latter. In order to reduce the positional error during maneuver, an active vibration suppression is done. To this end, a feedback control is designed for robustness against disturbance on the basis of the linear equations and the LQR theory modified to have a prescribed degree of stability. The proposed control scheme shows satisfactory performances in experiments as well as in numerical simulations.

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The Design of Optimized Type-2 Fuzzy Neural Networks and Its Application (최적 Type-2 퍼지신경회로망 설계와 응용)

  • Kim, Gil-Sung;Ahn, Ihn-Seok;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.8
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    • pp.1615-1623
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    • 2009
  • In order to develop reliable on-site partial discharge (PD) pattern recognition algorithm, we introduce Type-2 Fuzzy Neural Networks (T2FNNs) optimized by means of Particle Swarm Optimization(PSO). T2FNNs exploit Type-2 fuzzy sets which have a characteristic of robustness in the diverse area of intelligence systems. Considering the on-site situation where it is not easy to obtain voltage phases to be used for PRPDA (Phase Resolved Partial Discharge Analysis), the PD data sets measured in the laboratory were artificially changed into data sets with shifted voltage phases and added noise in order to test the proposed algorithm. Also, the results obtained by the proposed algorithm were compared with that of conventional Neural Networks(NNs) as well as the existing Radial Basis Function Neural Networks (RBFNNs). The T2FNNs proposed in this study were appeared to have better performance when compared to conventional NNs and RBFNNs.

Fragile Watermarking Scheme Based on Wavelet Edge Features

  • Vaishnavi, D.;Subashini, T.S.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2149-2154
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    • 2015
  • This paper proposes a novel watermarking method to discover the tampers and localize it in digital image. The image which is to be used to generate a watermark is first wavelet decomposed and the edge feature from the sub bands of high frequency coefficients are retrieved to generate a watermark (Edge Feature Image) and which is to be embed on the cover image. Before embedding the watermark, the pixels of cover image are disordered through the Arnold Transform and this helps to upgrade the security of the watermark. The embedding of generated edge feature image is done only on the Least Significant Bit (LSB) of the cover image. The invisibleness and robustness of the proposed method is computed using Peak-Signal to Noise Ratio (PSNR) and Normalized Correlation (NC) and it proves that the proposed method delivers good results and the proposed method also detects and localizes the tampers efficiently. The invisibleness of proposed method is compared with the existing method and it proves that the proposed method is better.

Protection of Multimedia Content under Mobile Environment (이동 환경에서의 멀티미디어 콘텐츠 보호)

  • Kim, Hang-Rae;Park, Young
    • Proceedings of the Korea Contents Association Conference
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    • 2003.11a
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    • pp.124-127
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    • 2003
  • In this research, a watermarking scheme for multimedia content service under the mobile envrionment is proposed. The proposed watermarking scheme that adds robustness to the errors occured in the mobile envrionment existing the pathloss, fading, interference and noise was designed. In case of the multimedia content service under the mobile envrionment, Possible methods for important matters to be considered for the copyright protection, construction of the watermark and position of insertion and detection are also proposed. It is observed that a watermark is composed of information of the mobile user Insertion and detection of the watermark is implemented with CDMA technique in the frequency region.

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