• Title/Summary/Keyword: a Markov chain

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Markov Chain Monte Carol estimation in Two Successive Occasion Sampling with Radomized Response Model

  • Lee, Kay-O
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.211-224
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    • 2000
  • The Bayes estimation of the proportion in successive occasions sampling with randomized response model is discussed by means of Acceptance Rejection sampling. Bayesian estimation of transition probabilities in two successive occasions is suggested via Markov Chain Monte Carlo algorithm and its applicability is represented in a numerical example.

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Parameter Optimization and Uncertainty Analysis of the NWS-PC Rainfall-Runoff Model Coupled with Bayesian Markov Chain Monte Carlo Inference Scheme (Bayesian Markov Chain Monte Carlo 기법을 통한 NWS-PC 강우-유출 모형 매개변수의 최적화 및 불확실성 분석)

  • Kwon, Hyun-Han;Moon, Young-Il;Kim, Byung-Sik;Yoon, Seok-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4B
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    • pp.383-392
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    • 2008
  • It is not always easy to estimate the parameters in hydrologic models due to insufficient hydrologic data when hydraulic structures are designed or water resources plan are established. Therefore, uncertainty analysis are inevitably needed to examine reliability for the estimated results. With regard to this point, this study applies a Bayesian Markov Chain Monte Carlo scheme to the NWS-PC rainfall-runoff model that has been widely used, and a case study is performed in Soyang Dam watershed in Korea. The NWS-PC model is calibrated against observed daily runoff, and thirteen parameters in the model are optimized as well as posterior distributions associated with each parameter are derived. The Bayesian Markov Chain Monte Carlo shows a improved result in terms of statistical performance measures and graphical examination. The patterns of runoff can be influenced by various factors and the Bayesian approaches are capable of translating the uncertainties into parameter uncertainties. One could provide against an unexpected runoff event by utilizing information driven by Bayesian methods. Therefore, the rainfall-runoff analysis coupled with the uncertainty analysis can give us an insight in evaluating flood risk and dam size in a reasonable way.

Comparison on Track Formation Range between TWS and Adaptive Tracking Using Markov Chain Analysis in a Radar System (레이더에서의 Markov Chain 분석을 이용한 TWS 방식과 Adaptive Tracking 방식의 추적 형성 거리 비교)

  • Ahn, Chang-Soo;Roh, Ji-Eun;Jang, Sung-Hoon;Kim, Seon-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.5
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    • pp.574-580
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    • 2013
  • Compared with the TWS(Track While Scan) tracking that uses scan-to-scan correlation at search illuminations for targets track, a phased array radar can use adaptive tracking which assigns additional track illuminations and the track formation range can be improved as a result. In this paper, an adaptive tracking, the search and track illuminations of a target are synchronized such that the extra illuminations are evenly distributed between the search illuminations, is proposed. Markov chain and track formation range for the proposed adaptive tracking are shown with them for the conventional TWS. The simulation result shows that the proposed adaptive tracking has improved track formation range by 27.6 % compared with the conventional TWS tracking under same track confirmation criterion.

Energy Harvesting in Multi-relay Multiuser Networks based on Two-step Selection Scheme

  • Guo, Weidong;Tian, Houyuan;Wang, Qing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4180-4196
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    • 2017
  • In this paper, we analyze average capacity of an amplify-and-forward (AF) cooperative communication system model in multi-relay multiuser networks. In contrast to conventional cooperative networks, relays in the considered network have no embedded energy supply. They need to rely on the energy harvested from the signals broadcasted by the source for their cooperative information transmission. Based on this structure, a two-step selection scheme is proposed considering both channel state information (CSI) and battery status of relays. Assuming each relay has infinite or finite energy storage for accumulating the energy, we use the infinite or finite Markov chain to capture the evolution of relay batteries and certain simplified assumptions to reduce computational complexity of the Markov chain analysis. The approximate closed-form expressions for the average capacity of the proposed scheme are derived. All theoretical results are validated by numerical simulations. The impacts of the system parameters, such as relay or user number, energy harvesting threshold and battery size, on the capacity performance are extensively investigated. Results show that although the performance of our scheme is inferior to the optimal joint selection scheme, it is still a practical scheme because its complexity is much lower than that of the optimal scheme.

Markov Chain Monte Carlo simulation based Bayesian updating of model parameters and their uncertainties

  • Sengupta, Partha;Chakraborty, Subrata
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.103-115
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    • 2022
  • The prediction error variances for frequencies are usually considered as unknown in the Bayesian system identification process. However, the error variances for mode shapes are taken as known to reduce the dimension of an identification problem. The present study attempts to explore the effectiveness of Bayesian approach of model parameters updating using Markov Chain Monte Carlo (MCMC) technique considering the prediction error variances for both the frequencies and mode shapes. To remove the ergodicity of Markov Chain, the posterior distribution is obtained by Gaussian Random walk over the proposal distribution. The prior distributions of prediction error variances of modal evidences are implemented through inverse gamma distribution to assess the effectiveness of estimation of posterior values of model parameters. The issue of incomplete data that makes the problem ill-conditioned and the associated singularity problem is prudently dealt in by adopting a regularization technique. The proposed approach is demonstrated numerically by considering an eight-storey frame model with both complete and incomplete modal data sets. Further, to study the effectiveness of the proposed approach, a comparative study with regard to accuracy and computational efficacy of the proposed approach is made with the Sequential Monte Carlo approach of model parameter updating.

Numerical Iteration for Stationary Probabilities of Markov Chains

  • Na, Seongryong
    • Communications for Statistical Applications and Methods
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    • v.21 no.6
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    • pp.513-520
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    • 2014
  • We study numerical methods to obtain the stationary probabilities of continuous-time Markov chains whose embedded chains are periodic. The power method is applied to the balance equations of the periodic embedded Markov chains. The power method can have the convergence speed of exponential rate that is ambiguous in its application to original continuous-time Markov chains since the embedded chains are discrete-time processes. An illustrative example is presented to investigate the numerical iteration of this paper. A numerical study shows that a rapid and stable solution for stationary probabilities can be achieved regardless of periodicity and initial conditions.

SITE-DEPENDENT IRREGULAR RANDOM WALK ON NONNEGATIVE INTEGERS

  • Konsowa, Mokhtar-H.;Okasha, Hassan-M.
    • Journal of the Korean Statistical Society
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    • v.32 no.4
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    • pp.401-409
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    • 2003
  • We consider a particle walking on the nonnegative integers and each unit of time it makes, given it is at site k, either a jump of size m distance units to the right with probability $p_{k}$ or it goes back (falls down) to its starting point 0, a retaining barrier, with probability $v_{k}\;=\;1\;-\;p_{k}$. This is a Markov chain on the integers $mZ^{+}$. We show that if $v_{k}$ has a nonzero limit, then the Markov chain is positive recurrent. However, if $v_{k}$ speeds to 0, then we may get transient Markov chain. A critical speeding rate to zero is identified to get transience, null recurrence, and positive recurrence. Another type of random walk on $Z^{+}$ is considered in which a particle moves m distance units to the right or 1 distance unit to left with probabilities $p_{k}\;and\;q_{k}\;=\;1\;-\;p_{k}$, respectively. A necessary condition to having a stationary distribution and positive recurrence is obtained.

A Prediction Method using Markov chain for Step Size Control in FMI based Co-simulation (FMI기반 co-simulation에서 step size control을 위한 Markov chain을 사용한 예측 방법)

  • Hong, Seokjoon;Lim, Ducsun;Kim, Wontae;Joe, Inwhee
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1430-1439
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    • 2019
  • In Functional Mockup Interface(FMI)-based co-simulation, a bisectional algorithm can be used to find the zerocrossing point as a way to improve the accuracy of the simulation results. In this paper, the proposed master algorithm(MA) analyzes the repeated interval graph and predicts the next interval by applying the Markov Chain to the step size. In the simulation, we propose an algorithm to minimize the rollback by storing the step size that changes according to the graph type as an array and applying it to the next prediction interval when the rollback occurs in the simulation. Simulation results show that the proposed algorithm reduces the simulation time by more than 20% compared to the existing algorithm.

Reliability Analysis of Stowage System of Container Crane using Subset Simulation with Markov Chain Monte Carlo Sampling (마르코프 연쇄 몬테 카를로 샘플링과 부분집합 시뮬레이션을 사용한 컨테이너 크레인 계류 시스템의 신뢰성 해석)

  • Park, Wonsuk;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.54-59
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    • 2017
  • This paper presents an efficient finite analysis model and a simulation-based reliability analysis method for stowage device system failure of a container crane with respect to lateral load. A quasi-static analysis model is introduced to simulate the nonlinear resistance characteristics and failure of tie-down and stowage pin, which are the main structural stowage devices of a crane. As a reliability analysis method, a subset simulation method is applied considering the uncertainties of later load and mechanical characteristic parameters of stowage devices. An efficient Markov chain Monte Carlo (MCMC) method is applied to sample random variables. Analysis result shows that the proposed model is able to estimate the probability of failure of crane system effectively which cannot be calculated practically by crude Monte Carlo simulation method.