• Title/Summary/Keyword: bayesian filter posterior

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Real-Time Motion Estimation Algorithm for Mobile Surveillance Robot (모바일 감시 로봇을 위한 실시간 움직임 추정 알고리즘)

  • Han, Cheol-Hoon;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.311-316
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    • 2009
  • This paper presents the motion estimation algorithm on real-time for mobile surveillance robot using particle filter. the particle filter that based on the monte carlo's sampling method, use bayesian conditional probability model which having prior distribution probability and posterior distribution probability. However, the initial probability density was set to define randomly in the most of particle filter. In this paper, we find first the initial probability density using Sum of Absolute Difference(SAD). and we applied it in the partical filter. In result, more robust real-time estimation and tracking system on the randomly moving object was realized in the mobile surveillance robot environments.

Visual Attention Model Based on Particle Filter

  • Liu, Long;Wei, Wei;Li, Xianli;Pan, Yafeng;Song, Houbing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.8
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    • pp.3791-3805
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    • 2016
  • The visual attention mechanism includes 2 attention models, the bottom-up (B-U) and the top-down (T-D), the physiology of which have not yet been accurately described. In this paper, the visual attention mechanism is regarded as a Bayesian fusion process, and a visual attention model based on particle filter is proposed. Under certain particular assumed conditions, a calculation formula of Bayesian posterior probability is deduced. The visual attention fusion process based on the particle filter is realized through importance sampling, particle weight updating, and resampling, and visual attention is finally determined by the particle distribution state. The test results of multigroup images show that the calculation result of this model has better subjective and objective effects than that of other models.

Wavelet Denoising based on a Bayesian Approach (Bayesian 방법에 의한 잡음감소 방법에 관한 연구)

  • Lee, Moon-Jik;Chung, Chin-Hyun
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.2956-2958
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    • 1999
  • The classical solution to the noise removal problem is the Wiener filter, which utilizes the second-order statistics of the Fourier decomposition. We discuss a Bayesian formalism which gives rise to a type of wavelet threshold estimation in non-parametric regression. A prior distribution is imposed on the wavelet coefficients of the unknown response function, designed to capture the sparseness of wavelet expansion common to most application. For the prior specified, the posterior median yields a thresholding procedure

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A Study on Enhancing Outdoor Pedestrian Positioning Accuracy Using Smartphone and Double-Stacked Particle Filter (스마트폰과 Double-Stacked 파티클 필터를 이용한 실외 보행자 위치 추정 정확도 개선에 관한 연구)

  • Kwangjae Sung
    • Journal of the Semiconductor & Display Technology
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    • v.22 no.2
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    • pp.112-119
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    • 2023
  • In urban environments, signals of Global Positioning System (GPS) can be blocked and reflected by tall buildings, large vehicles, and complex components of road network. Therefore, the performance of the positioning system using the GPS module in urban areas can be degraded due to the loss of GPS signals necessary for the position estimation. To deal with this issue, various localization schemes using inertial measurement unit (IMU) sensors, such as gyroscope and accelerometer, and Bayesian filters, such as Kalman filter (KF) and particle filter (PF), have been designed to enhance the performance of the GPS-based positioning system. Among Bayesian filters, the PF has been widely used for the target tracking and vehicle navigation, since it can provide superior performance in estimating the state of a dynamic system under nonlinear/non-Gaussian circumstance. This paper presents a positioning system that uses the double-stacked particle filter (DSPF) as well as the accelerometer, gyroscope, and GPS receiver on the smartphone to provide higher pedestrian positioning accuracy in urban environments. The DSPF employs a nonparametric technique (Parzen-window) to create the multimodal target distribution that approximates the posterior distribution. Experimental results show that the DSPF-based positioning system can provide the significant improvement of the pedestrian position estimation in urban environments.

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Evolution Strategies Based Particle Filters for Simultaneous State and Parameter Estimation of Nonlinear Stochastic Models

  • Uosaki, K.;Hatanaka, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1765-1770
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    • 2005
  • Recently, particle filters have attracted attentions for nonlinear state estimation. In this approaches, a posterior probability distribution of the state variable is evaluated based on observations in simulation using so-called importance sampling. We proposed a new filter, Evolution Strategies based particle (ESP) filter to circumvent degeneracy phenomena in the importance weights, which deteriorates the filter performance, and apply it to simultaneous state and parameter estimation of nonlinear state space models. Results of numerical simulation studies illustrate the applicability of this approach.

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A Real-time Particle Filtering Framework for Robust Camera Tracking in An AR Environment (증강현실 환경에서의 강건한 카메라 추적을 위한 실시간 입자 필터링 기법)

  • Lee, Seok-Han
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.597-606
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    • 2010
  • This paper describes a real-time camera tracking framework specifically designed to track a monocular camera in an AR workspace. Typically, the Kalman filter is often employed for the camera tracking. In general, however, tracking performances of conventional methods are seriously affected by unpredictable situations such as ambiguity in feature detection, occlusion of features and rapid camera shake. In this paper, a recursive Bayesian sampling framework which is also known as the particle filter is adopted for the camera pose estimation. In our system, the camera state is estimated on the basis of the Gaussian distribution without employing additional uncertainty model and sample weight computation. In addition, the camera state is directly computed based on new sample particles which are distributed according to the true posterior of system state. In order to verify the proposed system, we conduct several experiments for unstable situations in the desktop AR environments.