• Title/Summary/Keyword: Filter convergence

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Design of Robust Fuzzy-Logic Tracker for Noise and Clutter Contaminated Trajectory based on Kalman Filter

  • Byeongil Kim
    • Journal of the Korean Society of Industry Convergence
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    • v.27 no.2_1
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    • pp.249-256
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    • 2024
  • Traditional methods for monitoring targets rely heavily on probabilistic data association (PDA) or Kalman filtering. However, achieving optimal performance in a densely congested tracking environment proves challenging due to factors such as the complexities of measurement, mathematical simplification, and combined target detection for the tracking association problem. This article analyzes a target tracking problem through the lens of fuzzy logic theory, identifies the fuzzy rules that a fuzzy tracker employs, and designs the tracker utilizing fuzzy rules and Kalman filtering.

AN ISOMORPHISM FOR INFINITE DIMENSIONAL CALCULUS

  • Lee, Seok-Jong;Min, Kyung-Chan
    • Communications of the Korean Mathematical Society
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    • v.13 no.3
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    • pp.475-480
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    • 1998
  • We show that the foundational isomorphism exists in the category of filter convergence spaces which contains the category of Banach spaces as a replete subcategory.

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Effect of filters and reconstruction method on Cu-64 PET image

  • Lee, Seonhwa;Kim, Jung min;Kim, Jung Young;Kim, Jin Su
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.3 no.2
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    • pp.65-71
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    • 2017
  • To assess the effects of filter and reconstruction of Cu-64 PET data on Siemens scanner, the various reconstruction algorithm with various filters were assessed in terms of spatial resolution, non-uniformity (NU), recovery coefficient (RC), and spillover ratio (SOR). Image reconstruction was performed using filtered backprojection (FBP), 2D ordered subset expectation maximization (OSEM), 3D reprojection algorithm (3DRP), and maximum a posteriori algorithms (MAP). For the FBP reconstruction, ramp, butterworth, hamming, hanning, or parzen filters were used. Attenuation or scatter correction were performed to assess the effect of attenuation and scatter correction. Regarding spatial resolution, highest achievable volumetric resolution was $3.08mm^3$ at the center of FOV when MAP (${\beta}=0.1$) reconstruction method was used. SOR was below 4% for FBP when ramp, Hamming, Hanning, or Shepp-logan filter were used. The lowest NU (highest uniform) after attenuation & scatter correction was 5.39% when FBP (parzen filter) was used. Regarding RC, 0.9 < RC < 1.1 was obtained when OSEM (iteration: 10) was used when attenuation and scatter correction were applied. In this study, image quality of Cu-64 on Siemens Inveon PET was investigated. This data will helpful for the quantification of Cu-64 PET data.

VPN-Filter Malware Techniques and Countermeasures in IoT Environment (사물인터넷 환경에서의 VPN-Filter malware 기술과 대응방법)

  • Kim, Seung-Ho;Lee, Keun-Ho
    • Journal of Convergence for Information Technology
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    • v.8 no.6
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    • pp.231-236
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    • 2018
  • Recently, a wide variety of IoT environment is being created due to the rapid development of information and communication technology. And accordingly in a variety of network structures, a countless number of attack techniques and new types of vulnerabilities are producing a social disturbance. In May of 2018, Talos Intelligence, the Cisco threat intelligence team has newly discovered 'VPN-Filter', which constitutes a large-scale IoT-based botnet, is infecting consumer routers in over 54 countries around the world. In this paper, types of IoT-based botnets and the attack techniques utilizing botnet will be examined and the countermeasure technique through EXIF metadata removal method which is the cause of connection method of C & C Server will be proposed by examining the characteristics of attack vulnerabilities and attack scenarios of VPN-Filter.

FIR Fixed-Interval Smoothing Filter for Discrete Nonlinear System with Modeling Uncertainty and Its Application to DR/GPS Integrated Navigation System (모델링 불확실성을 갖는 이산구조 비선형 시스템을 위한 유한 임펄스 응답 고정구간 스무딩 필터 및 DR/GPS 결합항법 시스템에 적용)

  • Cho, Seong Yun;Kim, Kyong-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.5
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    • pp.481-487
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    • 2013
  • This paper presents an FIR (Finite Impulse Response) fixed-interval smoothing filter for fast and exact estimating state variables of a discrete nonlinear system with modeling uncertainty. Conventional IIR (Infinite Impulse Response) filter and smoothing filter can estimate state variables of a system with an exact model when the system is observable. When there is an uncertainty in the system model, however, conventional IIR filter and smoothing filter may cause large errors because the filters cannot estimate the state variables corresponding to the uncertain model exactly. To solve this problem, FIR filters that have fast estimation properties and have robustness to the modeling uncertainty have been developed. However, there is time-delay estimation phenomenon in the FIR filter. The FIR smoothing filter proposed in this paper makes up for the drawbacks of the IIR filter, IIR smoothing filter, and FIR filter. Therefore, the FIR smoothing filter has good estimation performance irrespective of modeling uncertainty. The proposed FIR smoothing filter is applied to the integrated navigation system composed of a magnetic compass based DR (Dead Reckoning) and a GPS (Global Positioning System) receiver. Even when the magnetic compass error that changes largely as the surrounding magnetic field is modeled as a random constant, it is shown that the FIR smoothing filter can estimate the varying magnetic compass error fast and exactly with simulation results.

On the Convergence Speed of Nonlinear Least-Squares IIR Adaptive Filter (비선형 무한 응답 최소자승형 적응 여파기의 수렴속도에 관한 연구)

  • 김화종
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1987.11a
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    • pp.58-60
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    • 1987
  • In this paper, we investigate an infinite impulse response adaptive digital filter based on the nonlinear least-squares algorithm, and compare its convergence speed to that of a self-orthogonalizing IIR ADF which is known to have fastest convergence. By simulation, it is shown that the NLS IIR ADF converges faster than other known IIR ADF's, especially for a low-order case.

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fast running FIR filter structure based on Wavelet adaptive algorithm for computational complexity (웨이블렛 기반 적응 알고리즘의 계산량 감소에 적합한 Fast running FIR filter에 관한 연구)

  • Lee, Jae-Kyun;Lee, Chae-Wook
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2005.11a
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    • pp.250-255
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    • 2005
  • In this paper, we propose a new fast running FIR filter structure that improves the convergence speed of adaptive signal processing and reduces the computational complexity. The proposed filter is applied to wavelet based adaptive algorithm. Actually we compared the performance of the proposed algorithm with other algorithm using computer simulation of adaptive noise canceler based on synthesis speech. As the result, the frequency domain algorithm is prefer than the existent time domain. we analyzed the Wavelet algorithm, short-length fast running FIR algorithm, fast-short-length fast running FIR algorithm and proposed algorithm.

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A Study on the Fast Converging Algorithm for LMS Adaptive Filter Design (LMS 적응 필터 설계를 위한 고속 수렴 알고리즘에 관한 연구)

  • 신연기;이종각
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.5
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    • pp.12-19
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    • 1982
  • In general the design methods of adaptive filter are divided into two categories, one is based upon the local parameter optimization theory and the other is based upon stability theory. Among the various design techniques, the LMS algorithm by steepest-descent method which is based upon local parameter optimization theory is used widely. In designing the adaptive filter, the most important factor is the convergence rate of the algorithm. In this paper a new algorithm is proposed to improve the convergence rate of adaptive firter compared with the commonly used LMS algorithm. The faster convergence rate is obtained by adjusting the adaptation gain of LMS algorithm. And various aspects of improvement of the adaptive filter characteristics are discussed in detail.

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Performance Improvement of Tree Structured Subband Filtering (트리구조 필터뱅크를 이용한 서브밴드 필터링에서의 수렴 성능 향상)

  • 최창권;조병모
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.2
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    • pp.407-416
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    • 2000
  • Adaptive digital filtering and noise cancelling technique using a tree structured filter bank are presented to reduce a undesirable aliasing due to the decimation of filtered output and improve the performance in terms of mean-square error and the convergence speed using a aliasing canceller. A signal is split into two subband by analysis filter bank and decimated by decimator and reconstructed by interpolation technique and synthesis filter bank. A variable step-size LMS algorithm is used to improve the convergence speed in case of existing the measurement noise in desired input of filter. It is shown by computer simulation that the proposed subband structure in this paper is superior to conventional subband filter structure in terms of mean-square error and convergence speed.

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